Methods and Systems for LIDAR Optics Alignment

ABSTRACT

A method is provided that involves mounting a transmit block and a receive block in a LIDAR device to provide a relative position between the transmit block and the receive block. The method also involves locating a camera at a given position at which the camera can image light beams emitted by the transmit block and can image the receive block. The method also involves obtaining, using the camera, a first image indicative of light source positions of one or more light sources in the transmit block and a second image indicative of detector positions of one or more detectors in the receive block. The method also involves determining at least one offset based on the first image and the second image. The method also involves adjusting the relative position between the transmit block and the receive block based at least in part on the at least one offset.

BACKGROUND

Unless otherwise indicated herein, the materials described in thissection are not prior art to the claims in this application and are notadmitted to be prior art by inclusion in this section.

A LIDAR can estimate distance to environmental features while scanningthrough a scene to assemble a “point cloud” indicative of reflectivesurfaces in the environment. Individual points in the point cloud can bedetermined by transmitting a laser pulse and detecting a returningpulse, if any, reflected from an object in the environment, anddetermining the distance to the object according to the time delaybetween the transmission of the transmitted pulse and the reception ofthe reflected pulse. A laser, or set of lasers, can be rapidly andrepeatedly scanned across a scene to provide continuous real-timeinformation on distances to reflective objects in the scene. Combiningthe measured distances and the orientation of the laser(s) whilemeasuring each distance allows for associating a three-dimensionalposition with each returning pulse. In this way, a three-dimensional mapof points indicative of locations of reflective features in theenvironment can be generated for the entire scanning zone.

SUMMARY

In one example, a method is provided that involves mounting a transmitblock and a receive block in a light detection and ranging (LIDAR)device to provide a relative position between the transmit block and thereceive block. The transmit block may include one or more light sourcesconfigured to emit light at a source wavelength. The receive block mayinclude one or more detectors configured to detect light at the sourcewavelength. The method further involves locating a camera at a givenposition at which the camera, when focused at infinity, can image lightbeams emitted by the one or more light sources and can image the one ormore detectors. The method further involves obtaining a first imageusing the camera located at the given position and focused at infinity.The first image may be indicative of light source positions of the oneor more light sources. The method further involves obtaining a secondimage using the camera located at the given position and focused atinfinity. The second image may be indicative of detector positions ofthe one or more detectors in the receive block. The method furtherinvolves determining at least one offset based on the light sourcepositions indicated by the first image and the detector positionsindicated by the second image. The method further involves adjusting therelative position between the transmit block and the receive block basedat least in part on the at least one offset.

In another example, a system is provided that includes a mountingplatform to mount a light detection and ranging (LIDAR) device thatprovides a relative position between a transmit block in the LIDARdevice and a receive block in the LIDAR device. The transmit block mayinclude one or more light sources configured to emit light at a sourcewavelength. The receive block may include one or more detectorsconfigured to detect light at the source wavelength. The system alsoincludes a camera located at a given position at which the camera, whenfocused at infinity, can image light beams emitted by the one or morelight sources and can image the one or more detectors. The system alsoincludes an alignment apparatus configured to adjust the relativeposition between the transmit block and the receive block. The systemalso includes a controller configured to obtain a first image from thecamera located at the given position and focused at infinity. The firstimage may be indicative of light source positions of the one or morelight sources. The controller is also configured to obtain a secondimage from the camera located at the given position and focused atinfinity. The second image may be indicative of detector positions ofthe one or more detectors in the receive block. The controller is alsoconfigured to determine at least one offset based on the light sourcepositions indicated by the first image and the detector positionsindicated by the second image. The controller is also configured tocause the alignment apparatus to adjust the relative position betweenthe transmit block and the receive block based at least in part on theat least one offset.

In yet another example, a system is provided that includes a means formounting a transmit block and a receive block in a light detection andranging (LIDAR) device to provide a relative position between thetransmit block and the receive block. The transmit block may include oneor more light sources configured to emit light at a source wavelength.The receive block may include one or more detectors configured to detectlight at the source wavelength. The system also comprises means forlocating a camera at a given position at which the camera, when focusedat infinity, can image light beams emitted by the one or more lightsources and can image the one or more detectors. The system alsocomprises means for obtaining a first image using the camera located atthe given position and focused at infinity. The first image may beindicative of light source positions of the one or more light sources.The system also comprises means for obtaining a second image using thecamera located at the given position and focused at infinity. The secondimage may be indicative of detector positions of the one or moredetectors in the receive block. The system also comprises means fordetermining at least one offset based on the light source positionsindicated by the first image and the detector positions indicated by thesecond image. The system also comprises means for adjusting the relativeposition between the transmit block and the receive block based at leastin part on the at least one offset.

These as well as other aspects, advantages, and alternatives, willbecome apparent to those of ordinary skill in the art by reading thefollowing detailed description, with reference where appropriate to theaccompanying figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a block diagram of a system, according to an exampleembodiment.

FIG. 2A illustrates a LIDAR device, according to an example embodiment.

FIG. 2B is a cross-section view of the LIDAR device shown in FIG. 2A.

FIG. 2C is a perspective view of the LIDAR device shown in FIG. 2A withvarious components removed to illustrate an interior of the LIDARdevice.

FIG. 3 illustrates a transmit block, according to an example embodiment.

FIG. 4A is a view of a light source, according to an example embodiment.

FIG. 4B is a view of the light source of FIG. 4A in combination with acylindrical lens, according to an example embodiment.

FIG. 4C is another view of the light source and cylindrical lenscombination of FIG. 4B, according to an example embodiment.

FIG. 5A illustrates a receive block, according to an example embodiment.

FIG. 5B illustrates a side view of three detectors included in thereceive block of FIG. 5A.

FIG. 6A illustrates another LIDAR device, according to an exampleembodiment.

FIG. 6B illustrates a partial cross-section view of the LIDAR device ofFIG. 6A.

FIG. 6C illustrates a partial cross-section view of the optics assemblyin the LIDAR device of FIG. 6A.

FIG. 7A illustrates a system, according to an example embodiment.

FIG. 7B illustrates an arrangement of the system shown in FIG. 7A wherethe light filter is not interposed between the LIDAR device and thecamera.

FIG. 7C illustrates a partial view of the system shown in FIGS. 7A-7B.

FIG. 8 illustrates another system, according to an example embodiment.

FIG. 9 is a flowchart of a method, according to an example embodiment.

FIG. 10 illustrates an image indicative of light source positions,according to an example embodiment.

FIG. 11 illustrates an image indicative of detector positions, accordingto an example embodiment.

FIG. 12 illustrates an image in a scenario where light sources anddetectors are aligned, according to an example embodiment.

FIG. 13 illustrates an image in a scenario where light sources anddetectors have an up/down offset, according to an example embodiment.

FIG. 14 illustrates an image in a scenario where light sources anddetectors have a left/right offset, according to an example embodiment.

FIG. 15 illustrates an image in a scenario where light sources anddetectors have a forward/backward offset, according to an exampleembodiment.

FIG. 16 illustrates an image in a scenario where light sources anddetectors have a roll offset, according to an example embodiment.

FIG. 17 illustrates an image in a scenario where light sources anddetectors have a yaw offset, according to an example embodiment.

FIG. 18 illustrates an image in a scenario where light sources anddetectors have a pitch offset, according to an example embodiment.

FIG. 19 illustrates an image indicative of a defect or an aberration,according to an example embodiment.

FIG. 20 is a flowchart of another method, according to an exampleembodiment.

FIG. 21 illustrates a partial cross-section view of yet another system,according to an example embodiment.

FIG. 22 illustrates a front-view of a camera, according to an exampleembodiment.

DETAILED DESCRIPTION

The following detailed description describes various features andfunctions of the disclosed systems, devices and methods with referenceto the accompanying figures. In the figures, similar symbols identifysimilar components, unless context dictates otherwise. The illustrativesystem, device and method embodiments described herein are not meant tobe limiting. It may be readily understood by those skilled in the artthat certain aspects of the disclosed systems, devices and methods canbe arranged and combined in a wide variety of different configurations,all of which are contemplated herein.

Within examples, a LIDAR device may include a transmit block and areceive block. The transmit block may include one or more light sourcesthat transmit light for propagation away from the LIDAR device toward anenvironment of the LIDAR device. In turn, the transmitted light mayreflect off one or more objects in the environment, and the reflectedlight may propagate back toward the LIDAR device. Further, the receiveblock may include one or more detectors to detect the reflected light.Through this process, a computing system may process data from the LIDARdevice pertaining to the reflected light to determine positions and/orcharacteristics of various objects in the environment of the LIDARdevice.

To facilitate operation of the LIDAR device, a light beam emitted by agiven light source and reflected back toward the LIDAR device isreceived by a corresponding detector. Within examples, systems andmethods are provided for alignment of light source(s) and detector(s) ina LIDAR device.

FIG. 1 is a block diagram of a system 100, according to an exampleembodiment. The system 100 includes a mounting platform 102, analignment apparatus 160, and a controller 180. The system 100 mayoptionally include an auxiliary light source 170.

The mounting platform 102 may provide a platform for mounting some orall of the components of the system 100. As shown, the mounting platform102 mounts a LIDAR device 104 and a camera 106. In some examples, themounting platform 102 may also mount a light filter 108. Further, insome examples, the mounting platform 102 may also mount an actuator 112.Accordingly, the mounting platform 102 may be formed from one or moresolid materials suitable for supporting the various components, such asplastics or metals among other possibilities. In some examples, some ofthe components shown to be mounted on the mounting platform 102 mayalternatively be mounted to a separate structure (not shown) orotherwise coupled to the system 100. For instance, the camera 106 and/orthe light filter 108 may be alternatively positioned and/or mountedoutside the mounting platform 102.

The LIDAR device 104 includes a transmit block 120 and a receive block130. As shown, in some examples, the LIDAR device 104 may optionallyinclude a lens 150.

The transmit block 120 includes one or more light sources 122 that maybe configured to emit one or more light beams 124. Although not shown inFIG. 1, the transmit block 120 may include additional components such asa mirror or an exit aperture to condition and/or redirect the lightbeams 124. The one or more light sources 122 may include laser diodes,light emitting diodes (LEDs), vertical cavity surface emitting lasers(VCSEL), organic light emitting diodes (OLEDs), polymer light emittingdiodes (PLED), light emitting polymers (LEP), liquid crystal displays(LCD), microelectromechanical systems (MEMS), or any other deviceconfigured to selectively transmit, reflect, and/or emit light beams 124at a source wavelength. The source wavelength, for example, may includeultraviolet, visible, and/or infrared portions of the electromagneticspectrum. In one embodiment, the source wavelength is 905 nm.Additionally, in some examples, the light sources 122 may be configuredto emit the light beam(s) 124 in the form of pulses. In some examples,the light sources 122 may be disposed on one or more substrates (e.g.,printed circuit boards (PCB), flexible PCBs, etc.).

The receive block 130 includes one or more detectors 132 that may beconfigured to receive light from an environment of the LIDAR device 104.In one example, a given detector of the detectors 132 is configured andarranged to receive a given light beam of the light beams 124 that isreflected off an object in the environment of the LIDAR device 104toward the given detector. Through this process, for example, the LIDARdevice 104 may detect various objects in the environment by emittinglight beams 124 using the light sources 122 and detecting reflections ofthe light beams 124 using the detectors 132. Although not shown, in someexamples, the receive block 130 may include additional components suchas an inert gas, an entrance aperture (e.g., half-mirror), and/or anyother component to filter and/or condition light propagating toward thedetectors 132. The detector(s) 132 may comprise photodiodes, avalanchephotodiodes, phototransistors, cameras, active pixel sensors (APS),charge coupled devices (CCD), cryogenic detectors, or any other sensorof light. In one embodiment, the detector(s) 132 may be configured todetect light at the source wavelength (e.g., 905 nm, etc.) of the lightbeams 124 emitted by the light sources 122 and/or reflections thereof.

The lens 150 may be optionally included in the LIDAR device 104 and maybe configured to collimate the emitted light beams 124 and/or focuslight propagating toward the detectors 132. In one embodiment, the lens150 may be a single lens having an optical power to both collimate thelight beams 124 and focus light onto the detectors 132. In anotherembodiment, the lens 150 may include two separate lenses. For example, afirst lens may collimate the light beam(s) 124 emitted by the lightsource(s) 122, and a second lens may focus light propagating toward theLIDAR device 104 onto the detector(s) 132. Other lens configurations arepossible as well (e.g., multiple lenses for collimation and/or multiplelenses for focus, etc.).

In some examples, the LIDAR device 104 may include additional, fewer, ordifferent components than those shown in FIG. 1. Thus, in someembodiments, the system 100 may be utilized for assembly, manufacture,and/or calibration of various LIDAR devices having variousconfigurations, such as the LIDAR device 104 or any other LIDAR device.Accordingly, in some examples, the LIDAR device 104 may be removablymounted to the mounting platform 102 of the system 100 to facilitatesuch calibration or assembly.

In some examples, the various components of the LIDAR device 104 such asthe transmit block 120, receive block 130, and the lens 150 can beremovably mounted in predetermined positions within the LIDAR device 104to reduce burden of calibrating the arrangement of each component and/orsubcomponents included in each component. In these examples, the system100 may adjust the relative position between the transmit block 120 andthe receive block 130 to align the one or more light sources 122 withthe one or more detectors 132. Alternatively, in other examples, thesystem 100 may be configured to adjust the relative position betweeneach of the subcomponents (e.g., each light source of light sources 122,each detector of detectors 132, etc.).

The camera 106 may be any camera (e.g., a still camera, a video camera,etc.) configured to capture images of the LIDAR device 104. In someexamples, the camera 106 may be located at a given position at which thecamera 106 can image the light beams 124 emitted by the one or morelight sources 122, and can image the one or more detectors 132. In oneembodiment, the camera may be focused at infinity when capturing suchimages. By way of example, the camera may be mounted to have afield-of-view along the path of the light beams 124 (e.g., facing thelens 150, etc.).

As an example scenario for operation of the camera 106, the LIDAR device104 may then be configured to cause the light sources 122 to emit thelight beams 124 toward the camera 106. In turn, the camera 106 mayprovide a first image of the light beams 124. The first image, forinstance, may indicate light source position(s) (e.g., bright pixels inthe first image, etc.) of the light source(s) 122. In the scenario, thecamera may also obtain a second image indicative of detector position(s)of the detector(s) 132. Other scenarios are possible as well and aredescribed in greater detail within exemplary embodiments herein.

The light filter 108 may be optionally included in the system 100 tofacilitate capture and/or processing of the images described above. Forinstance, the light filter 108 may be positioned along a path of thelight beams 124 between the LIDAR device 104 and the camera 106. In oneexample, the light filter 108 may be configured to attenuate lightwithin a wavelength range that includes the source wavelength of thelight source(s) 122. In this example, the attenuation of the light mayfacilitate contrasting pixels in the first image that are associatedwith the light beams 124 against surrounding pixels. Further, in thisexample, the attenuation of the light may protect the camera 106 fromthe intensity of the light beams 124. In another example, the lightfilter 108 may be configured to attenuate light within anotherwavelength range that does not include the source wavelength of thelight source(s) 122. In this example, the images obtained by the camera106 may represent features of interest (e.g., light source(s) 122,detector(s) 132, etc.) in the LIDAR device 104 more clearly due to thelight filter 108 attenuating background light having other wavelengths.Other configurations of the light filter 108 are possible as well andare described in greater detail within exemplary embodiments herein.

The actuator 112 may be optionally included in the system 100. Theactuator 112 may be configured to adjust the position of the lightfilter 108. For instance, the actuator 112 may be configured to actuatethe light filter 108 to a first position where the light filter 108 isinterposed between the LIDAR device 104 and the camera 106, or to asecond position where the light filter 108 is not interposed between theLIDAR device 104 and the camera 106. Example actuators may includemotors, stepper motors, pneumatic actuators, hydraulic pistons, relays,solenoids, and piezoelectric actuators among other possibilities.

The alignment apparatus 160 may include any device that couples to oneor more of the components in the LIDAR device 104 to adjust the relativeposition between the transmit block 120 and the receive block 130. Byway of example, the alignment apparatus 160 may be a robotic arm thatphysically couples to the receive block 130 to rotate and/or translatethe position of the receive block 130 in the LIDAR 104. Alternatively oradditionally, for example, the robotic arm may adjust the position ofthe transmit block 120. In some examples, the alignment apparatus 160may adjust the relative position between the transmit block 120 and thereceive block 130 based on image(s) obtained by the camera 106. Forinstance, the alignment apparatus 160 may adjust the relative positionto align one or more of the light beams 124 emitted by the light sources122 with one or more of the detectors 132.

The system 100 may optionally include an auxiliary light source 170 thatemits light 174 at the source wavelength to illuminate the receive block130. The structure and form of the auxiliary light source 170 (e.g.,LED, etc.) may be similar to the light sources 122. In one example,where the camera 106 is configured to capture images when focused atinfinity for the source wavelength the light sources 122, the auxiliarylight source 170 may illuminate the detectors 132 to facilitate thecamera 106 obtaining the second image of the detectors 132 while alsofocused at infinity for the same source wavelength.

In some examples, the light filter 108 may be configured to remaininterposed between the camera 106 and the LIDAR device 104 duringcapture of the first image (e.g., of the light beams 124) and duringcapture of the second image (e.g., of the detectors 132). In theseexamples, the illuminating light 174 from the auxiliary light source 170may allow the camera 106 to capture an image of the detectors 132 whilethe light filter 108 is interposed.

In other examples, the system 100 may be configured to move the lightfilter 108 to another position other than the position between thecamera 106 and the LIDAR device 104 prior to the camera 106 obtainingthe second image of the detectors 132. For instance, the light filter108 may be moved by the actuator 112. In these examples, the camera 106may rely on background light to obtain the second image of the detectors132, or the system 100 may utilize the auxiliary light source 170 toilluminate the receive block 130.

The controller 180 may include one or more processors configured tooperate some or all of the components of the system 100 in line with thediscussion above. To that end, the controller 180 may be coupled to thevarious components via a wired or wireless interface (not shown). Insome examples, the controller 180 may execute program functions storedin a computer readable medium (not shown) to cause the system 100 toperform various functions and processes of the present method.

In a first example, the controller 180 may cause a power source (notshown) to provide power to the various components of the system 100. Ina second example, the controller 180 may cause the transmit block 120 ofthe LIDAR device 104 to emit the light beams 124. In a third example,the controller 180 may operate an actuator (not shown) to position thelight filter 108 between the LIDAR device 104 and the camera 106, or toposition the light filter 108 at any other position. In a third example,the controller 180 may operate the camera 106 to obtain the first image(e.g., of the light beams 124) and the second image (e.g., of thedetectors 132) in line with the discussion above. In a fourth example,the controller 180 may operate the alignment apparatus 160 to adjust therelative position between the transmit block 120 and the receive block130. In a fifth example, the controller 180 may operate the alignmentapparatus 160 to mount (or unmounts) various components (e.g., LIDARdevice 104, etc.) to the mounting platform 102. In a sixth example, thecontroller 180 may operate the auxiliary light source 170 to illuminatethe receive block 130 with light 174. In a seventh example, thecontroller 180 may operate the actuator 112 to move the light filter108. Other examples are possible as well and are described in greaterdetail within exemplary embodiments herein.

The system 100 may include additional, fewer, or different componentsthan those shown, and may perform other functions as well. In oneexample, the system 100 may include a display (not shown) for displayingimage(s) obtained using the camera 106. For instance, the display mayhave a graphical user interface (GUI) for displaying and/or interactingwith images captured by the camera 106, and a human operator or acomputer operator may interact with the GUI to adjust the relativeposition between the transmit block 120 and the receive block 130 bymanipulating the images in the GUI. Other procedures are possible aswell for controlling the system 100 in accordance with the presentdisclosure.

FIG. 2A illustrates a LIDAR device 200, according to an exampleembodiment. The LIDAR 200 illustrates an example LIDAR device that canbe used with a system such as the system 100. For instance, the LIDARdevice 200 may be similar to the LIDAR device 104 of the system 100, andmay be similarly mounted to the mounting platform 104 to adjust therelative position between light sources and detectors of the LIDAR 200.

As shown, the LIDAR device 200 includes a housing 210 and a lens 250.Additionally, light beams 204 emitted by the first LIDAR device 200propagate from the lens 250 along a viewing direction of the first LIDAR200 toward an environment of the LIDAR device 200, and reflect off oneor more objects in the environment as reflected light 206.

The housing 210 included in the LIDAR device 200 can provide a platformfor mounting the various components included in the LIDAR device 200.The housing 210 can be formed from any material capable of supportingthe various components of the LIDAR device 200 included in an interiorspace of the housing 210. For example, the housing 210 may be formedfrom a solid material such as plastic or metal among otherpossibilities.

In some examples, the housing 210 can be configured to have asubstantially cylindrical shape and to rotate about an axis of the LIDARdevice 200. For example, the housing 210 can have the substantiallycylindrical shape with a diameter of approximately 10 centimeters. Insome examples, the axis is substantially vertical. By rotating thehousing 210 that includes the various components, in some examples, athree-dimensional map of a 360-degree view of the environment of theLIDAR device 200 can be determined without frequent recalibration of thearrangement of the various components of the LIDAR device 200.Additionally or alternatively, in some examples, the LIDAR device 200can be configured to tilt the axis of rotation of the housing 210 tocontrol the field of view of the LIDAR device 200.

The lens 250 mounted to the housing 210 can have an optical power toboth collimate the emitted light beams 204, and focus the reflectedlight 205 from one or more objects in the environment of the LIDARdevice 200 onto detectors in the LIDAR device 200. In one example, thelens 250 has a focal length of approximately 120 mm. By using the samelens 250 to perform both of these functions, instead of a transmit lensfor collimating and a receive lens for focusing, advantages with respectto size, cost, and/or complexity can be provided.

The LIDAR device 200 can be mounted on a mounting structure 260 thatrotates about an axis to provide a 360-degree view of the environmentsurrounding the LIDAR device 200. In some examples, the mountingstructure 260 may comprise a movable platform that may tilt in one ormore directions to change the axis of rotation of the LIDAR device 200.

FIG. 2B is a cross-section view of the first LIDAR 200 shown in FIG. 2A.As shown, the housing 210 houses a transmit block 220, a receive block230, a shared space 240, and the lens 250. For purposes of illustration,FIG. 2B shows an x-y-z axis, in which the z-axis is in a substantiallyvertical direction.

The transmit block 220 includes a plurality of light sources 222 a-carranged along a curved focal surface 228 defined by the lens 250. Theplurality of light sources 222 a-c can be configured to emit,respectively, the plurality of light beams 202 a-c having wavelengthswithin a wavelength range. For example, the plurality of light sources222 a-c may comprise laser diodes that emit the plurality of light beams202 a-c having the wavelengths within the wavelength range. Theplurality of light beams 202 a-c are reflected by mirror 224 through anexit aperture 226 into the shared space 240 and towards the lens 250.

The light sources 222 a-c can include laser diodes, light emittingdiodes (LED), vertical cavity surface emitting lasers (VCSEL), organiclight emitting diodes (OLED), polymer light emitting diodes (PLED),light emitting polymers (LEP), liquid crystal displays (LCD),microelectromechanical systems (MEMS), or any other device configured toselectively transmit, reflect, and/or emit light to provide theplurality of emitted light beams 202 a-c. In some examples, the lightsources 222 a-c can be configured to emit the emitted light beams 202a-c in a wavelength range that can be detected by detectors 232 a-cincluded in the receive block 230. The wavelength range could, forexample, be in the ultraviolet, visible, and/or infrared portions of theelectromagnetic spectrum. In some examples, the wavelength range can bea narrow wavelength range, such as provided by lasers. In oneembodiment, the wavelength range includes a source wavelength of 905 nm.Additionally, the light sources 222 a-c can be configured to emit theemitted light beams 202 a-c in the form of pulses. In some examples, theplurality of light sources 222 a-c can be disposed on one or moresubstrates (e.g., printed circuit boards (PCB), flexible PCBs, etc.) andarranged to emit the plurality of light beams 202 a-c towards the exitaperture 226.

Although FIG. 2B shows that the curved focal surface 228 is curved inthe x-y plane, additionally or alternatively, the plurality of lightsources 222 a-c may be arranged along a focal surface that is curved ina vertical plane. For example, the curved focal surface 228 can have acurvature in a vertical plane, and the plurality of light sources 222a-c can include additional light sources arranged vertically along thecurved focal surface 228 and configured to emit light beams directed atthe mirror 224 and reflected through the exit aperture 226. In thisexample, the detectors 232 a-c may also include additional detectorsthat correspond to additional light sources of the light sources 222a-c. Further, in some examples, the light sources 222 a-c may includeadditional light sources arranged horizontally along the curved focalsurface 228. In one embodiment, the light sources 222 a-c may include 64light sources that emit light having a wavelength of 905 nm. Forinstance, the 64 light sources may be arranged in four columns, eachcomprising 16 light sources, along the curved focal surface 228. In thisinstance, the detectors 232 a-c may include 64 detectors that arearranged similarly (e.g., 4 columns comprising 16 detectors each, etc.)along curved focal surface 238. In other embodiments, the light sources222 a-c and the detectors 232 a-c may include additional or fewer lightsources and/or detectors than those shown in FIG. 2B.

Due to the arrangement of the plurality of light sources 222 a-c alongthe curved focal surface 228, the plurality of light beams 202 a-c, insome examples, may converge towards the exit aperture 226. Thus, inthese examples, the exit aperture 226 may be minimally sized while beingcapable of accommodating vertical and horizontal extents of theplurality of light beams 202 a-c. Additionally, in some examples, thecurved focal surface 228 can be defined by the lens 250. For example,the curved focal surface 228 may correspond to a focal surface of thelens 250 due to shape and composition of the lens 250. In this example,the plurality of light sources 222 a-c can be arranged along the focalsurface defined by the lens 250 at the transmit block.

The plurality of light beams 202 a-c propagate in a transmit path thatextends through the transmit block 220, the exit aperture 226, and theshared space 240 towards the lens 250. The lens 250 collimates theplurality of light beams 202 a-c to provide collimated light beams 204a-c into an environment of the LIDAR device 200. The collimated lightbeams 204 a-c correspond, respectively, to the plurality of light beams202 a-c. In some examples, the collimated light beams 204 a-c reflectoff one or more objects in the environment of the LIDAR device 200 asreflected light 206. The reflected light 206 may be focused by the lens250 into the shared space 240 as focused light 208 traveling along areceive path that extends through the shared space 240 onto the receiveblock 230. For example, the focused light 208 may be reflected by thereflective surface 242 as focused light 208 a-c propagating towards thereceive block 230.

The lens 250 may be capable of both collimating the plurality of lightbeams 202 a-c and focusing the reflected light 206 along the receivepath 208 towards the receive block 230 due to the shape and compositionof the lens 250. For example, the lens 250 can have an aspheric surface252 facing outside of the housing 210 and a toroidal surface 254 facingthe shared space 240. By using the same lens 250 to perform both ofthese functions, instead of a transmit lens for collimating and areceive lens for focusing, advantages with respect to size, cost, and/orcomplexity can be provided.

The exit aperture 226 is included in a wall 244 that separates thetransmit block 220 from the shared space 240. In some examples, the wall244 can be formed from a transparent material (e.g., glass) that iscoated with a reflective material 242. In this example, the exitaperture 226 may correspond to the portion of the wall 244 that is notcoated by the reflective material 242. Additionally or alternatively,the exit aperture 226 may comprise a hole or cut-away in the wall 244.

The focused light 208 is reflected by the reflective surface 242 anddirected towards an entrance aperture 234 of the receive block 230. Insome examples, the entrance aperture 234 may comprise a filtering windowconfigured to allow wavelengths in the wavelength range of the pluralityof light beams 202 a-c (e.g., source wavelength) emitted by theplurality of light sources 222 a-c and attenuate other wavelengths. Insome examples, the entrance aperture 234 may comprise a half-mirrorconfigured to reflect a portion of the focused light 208 a-c and allowanother portion of the focused light 208 a-c to propagate toward thedetectors 232 a-c. The focused light 208 a-c reflected by the reflectivesurface 242 from the focused light 208 a-c propagates, respectively,onto a plurality of detectors 232 a-c.

The plurality of detectors 232 a-c can be arranged along a curved focalsurface 238 of the receive block 230. Although FIG. 2B shows that thecurved focal surface 238 is curved along the x-y plane (horizontalplane), additionally or alternatively, the curved focal surface 238 canbe curved in a vertical plane. The curvature of the focal surface 238 isalso defined by the lens 250. For example, the curved focal surface 238may correspond to a focal surface of the light projected by the lens 250along the receive path at the receive block 230.

The detectors 232 a-c may comprise photodiodes, avalanche photodiodes,phototransistors, cameras, active pixel sensors (APS), charge coupleddevices (CCD), cryogenic detectors, or any other sensor of lightconfigured to receive focused light 208 a-c having wavelengths in thewavelength range of the emitted light beams 202 a-c (e.g., the sourcewavelength).

Each of the focused light 208 a-c corresponds, respectively, to theemitted light beams 202 a-c and is directed onto, respectively, theplurality of detectors 232 a-c. For example, the detector 232 a isconfigured and arranged to received focused light 208 a that correspondsto collimated light beam 204 a reflected of the one or more objects inthe environment of the LIDAR device 200. In this example, the collimatedlight beam 204 a corresponds to the light beam 202 a emitted by thelight source 222 a. Thus, the detector 232 a receives light that wasemitted by the light source 222 a, the detector 232 b receives lightthat was emitted by the light source 222 b, and the detector 232 creceives light that was emitted by the light source 222 c.

By comparing the received light 208 a-c with the emitted light beams 202a-c, at least one aspect of the one or more object in the environment ofthe LIDAR device 200 may be determined. For example, by comparing a timewhen the plurality of light beams 202 a-c were emitted by the pluralityof light sources 222 a-c and a time when the plurality of detectors 232a-c received the focused light 208 a-c, a distance between the LIDARdevice 200 and the one or more object in the environment of the LIDARdevice 200 may be determined. In some examples, other aspects such asshape, color, material, etc. may also be determined.

In some examples, the LIDAR device 200 may be rotated about an axis todetermine a three-dimensional map of the surroundings of the LIDARdevice 200. For example, the LIDAR device 200 may be rotated about asubstantially vertical axis as illustrated by arrow 290. Althoughillustrated that the LIDAR device 200 is rotated counter clock-wiseabout the axis as illustrated by the arrow 290, additionally oralternatively, the LIDAR device 200 may be rotated in the clockwisedirection. In some examples, the LIDAR device 200 may be rotated 360degrees about the axis. In other examples, the LIDAR device 200 may berotated back and forth along a portion of the 360 degree view of theLIDAR device 200. For example, the LIDAR device 200 may be mounted on aplatform that wobbles back and forth about the axis without making acomplete rotation.

Thus, the arrangement of the light sources 222 a-c and the detectors 232a-c may allow the LIDAR device 200 to have a particular verticalfield-of-view. In one example, the vertical FOV of the LIDAR device 200is 20°. Additionally, the rotation of the LIDAR device 200 allows theLIDAR device 200 to have a 360° horizontal FOV. Further, the rate ofrotation may allow the device to have a particular refresh rate. In oneexample, the refresh rate is 10 Hz. The refresh rate along with thearrangement of the light sources 222 a-c and the detectors 232 a-c mayalso allow the LIDAR device 300 to have a particular angular resolution.In one example, the angular resolution is 0.2°×0.3°. However, thevarious parameters such as the refresh rate and the angular resolutionmay vary according to the configuration of the LIDAR device 200.Further, in some examples, the LIDAR device 200 may include additional,fewer, or different components than those shown in FIGS. 2A-2B.

FIG. 2C is a perspective view of the LIDAR device 200 shown in FIG. 2Awith various components removed to illustrate an interior of the LIDARdevice 200. As shown, the various components of the LIDAR device 200 canbe removably mounted to the housing 210. For example, the transmit block220 may comprise one or more printed circuit boards (PCBs) that arefitted in the portion of the housing 210 where the transmit block 220can be mounted. Although FIG. 2C shows the transmit block 220 with onePCB, in some embodiments, the transmit block 320 may include multiplePCBs (not shown) that each include some of the plurality of lightsources 232 a-c. In one embodiment, each PCB in the transmit block mayinclude 16 light sources, and the transmit block 220 may include fourPCBs. Thus, in this embodiment, the LIDAR device 200 may include 64light sources. Other embodiments are possible as well where the transmitblock 220 includes a different number of light sources. Additionally,the receive block 230 may comprise a plurality of detectors (e.g.,detectors 232 a-c, etc.) mounted to a flexible substrate and can beremovably mounted to the housing 210 as a block that includes theplurality of detectors. Similarly, the lens 250 can be mounted toanother side of the housing 210.

FIG. 3 illustrates a transmit block 320, according to an exampleembodiment. Transmit block 320 may be similar to the transmit blocks 120and/or 220 described in FIGS. 1-2. For example, the transmit block 320includes a plurality of light sources 322 a-c similar to the pluralityof light sources 222 a-c included in the transmit block 220 of FIGS.2A-2C. Additionally, the light sources 322 a-c are arranged along afocal surface 328, which is curved in a vertical plane. The lightsources 322 a-c are configured to emit a plurality of light beams 302a-c that converge and propagate through an exit aperture 326 in a wall344.

Although the plurality of light sources 322 a-c can be arranged along afocal surface 328 that is curved in a vertical plane, additionally oralternatively, the plurality of light sources 322 a-c can be arrangedalong a focal surface that is curved in a horizontal plane or a focalsurface that is curved both vertically and horizontally. For example,the plurality of light sources 322 a-c can be arranged in a curved threedimensional grid pattern. For example, the transmit block 320 maycomprise a plurality of printed circuit boards (PCBs) vertically mountedsuch that a column of light sources such as the plurality of lightsources 322 a-c are along the vertical axis of each PCB and each of theplurality of PCBs can be arranged adjacent to other vertically mountedPCBs along a horizontally curved plane to provide the three dimensionalgrid pattern. Alternatively, in some examples, the light sources 322 a-cmay be arranged along any other surface such as a linear surface.Further, although the transmit block 320 is shown to include multiplelight sources 322 a-c, in some examples, the transmit block 320 mayinclude only one light source or a different number of light sourcesthan those shown in FIG. 3.

As shown in FIG. 3, the light beams 302 a-c converge towards the exitaperture 326 which allows the size of the exit aperture 326 to beminimized while accommodating vertical and horizontal extents of thelight beams 302 a-c similarly to the exit aperture 226 described in FIG.2B.

The light emitted by the light sources 222 a-c may be partiallycollimated to fit through the exit aperture 224. FIGS. 4A, 4B, and 4Cillustrate an example of how such partial collimation could be achieved.In this example, a light source 400 is made up of a laser diode 402 anda cylindrical lens 404. As shown in FIG. 4A, laser diode 402 has anaperture 406 with a shorter dimension corresponding to a fast axis 408and a longer dimension corresponding to a slow axis 410. FIGS. 4B and 4Cshow an uncollimated laser beam 412 being emitted from laser diode 402.Laser beam 412 diverges in two directions, one direction defined by fastaxis 408 and another, generally orthogonal direction defined by slowaxis 410. FIG. 4B shows the divergence of laser beam 412 along fast axis408, whereas FIG. 4C shows the divergence of laser beam 412 along slowaxis 410. Laser beam 412 diverges more quickly along fast axis 408 thanalong slow axis 410.

In one specific example, laser diode 402 is an Osram SPL DL90_3nanostack pulsed laser diode that emits pulses of light with a range ofwavelengths from about 896 nm to about 910 nm (a nominal wavelength of905 nm). In this specific example, the aperture has a shorter dimensionof about 10 microns, corresponding to its fast axis, and a longerdimension of about 200 microns, corresponding to its slow axis. Thedivergence of the laser beam in this specific example is about 25degrees along the fast axis and about 11 degrees along the slow axis. Itis to be understood that this specific example is illustrative only.Laser diode 402 could have a different configuration, different aperturesizes, different beam divergences, and/or emit different wavelengths.

As shown in FIGS. 4B and 4C, cylindrical lens 404 may be positioned infront of aperture 406 with its cylinder axis 414 generally parallel toslow axis 410 and perpendicular to fast axis 408. In this arrangement,cylindrical lens 404 can pre-collimate laser beam 412 along fast axis408, resulting in partially collimated laser beam 416. In some examples,this pre-collimation may reduce the divergence along fast axis 408 toabout one degree or less. Nonetheless, laser beam 416 is only partiallycollimated because the divergence along slow axis 410 may be largelyunchanged by cylindrical lens 404. Thus, whereas uncollimated laser beam412 emitted by laser diode has a higher divergence along fast axis 408than along slow axis 410, partially collimated laser beam 416 providedby cylindrical lens 404 may have a higher divergence along slow axis 410than along fast axis 408. Further, the divergences along slow axis 410in uncollimated laser beam 412 and in partially collimated laser beam416 may be substantially equal.

In one example, cylindrical lens 404 is a microrod lens with a diameterof about 600 microns that is placed about 250 microns in front ofaperture 406. The material of the microrod lens could be, for example,fused silica or a borosilicate crown glass, such as Schott BK7.Cylindrical lens 404 could also be used to provide magnification alongfast axis 408. For example, if the dimensions of aperture 406 are 10microns by 200 microns, as previously described, and cylindrical lens404 is a microrod lens as described above, then cylindrical lens 404 maymagnify the shorter dimension (corresponding to fast axis 408) by about20 times. This magnification effectively stretches out the shorterdimension of aperture 406 to about the same as the longer dimension. Asa result, when light from laser beam 416 is focused, for example, onto adetector, the focused spot could have a substantially square shapeinstead of the rectangular slit shape of aperture 406.

FIG. 5A illustrates a receive block 530, according to an exampleembodiment. FIG. 5B illustrates a side view of three detectors 532 a-cincluded in the receive block 530 of FIG. 5A. Receive block 530 may besimilar to the receive block 130 of FIG. 1 and/or the receive block 230of FIGS. 2B-2C. For example, the receive block 530 includes a pluralityof detectors 532 a-c arranged along a curved surface 538 defined by alens 550 similarly to the receive block 230, the detectors 232 a-c, andthe curved plane 238 described in FIG. 2B. Focused light 508 a-c fromlens 550 propagates along a receive path that includes a reflectivesurface 542 onto the detectors 532 a-c similar, respectively, to thefocused light 208 a-c, the lens 250, the reflective surface 242, and thedetectors 232 a-c described in FIG. 2B.

The receive block 530 comprises a flexible substrate 580 on which theplurality of detectors 532 a-c are arranged along the curved surface538. The flexible substrate 580 conforms to the curved surface 538 bybeing mounted to a receive block housing 590 having the curved surface538. As illustrated in FIG. 5B, the curved surface 538 includes thearrangement of the detectors 532 a-c curved along a vertical andhorizontal axis of the receive block 530.

In some embodiments, the number and arrangement of the detectors 532 a-cmay be different than those shown in FIGS. 5A-5B. For instance, thedetectors 532 a-c may be alternatively arranged along a linear surface,or may alternatively only include one detector, among otherpossibilities.

As noted above in the description of FIG. 1, the system 100 may be usedwith various LIDAR devices having various configurations, such as theLIDAR device 200 of FIGS. 2A-2C. FIG. 6A illustrates another LIDARdevice 600 that may be used with the system 100, according to an exampleembodiment.

As shown, the LIDAR device 600 includes an optics assembly 610, atransmit lens 652, a receive lens 654, a mirror 620, a pin 622, and amotor 670. For purposes of illustration, FIG. 6A shows an x-y-z axis, inwhich the z-axis is pointing out of the page, and the x-axis and y-axisdefine a horizontal plane along the surface of the page.

In some examples, the LIDAR device 600 may emit light that propagatesaway from the mirror 660 along a viewing direction of the LIDAR device600 (e.g., parallel to z-axis shown in FIG. 6A, etc.) toward anenvironment of the LIDAR device 600, and may receive reflected lightfrom one or more objects in the environment.

Accordingly, the optics assembly 610 may be configured to emit lightpulses towards the mirror 660 that are then reflected by the mirror 660towards the environment. Further, the optics assembly 610 may beconfigured to receive reflected light that is reflected off the mirror660. In one embodiment, the optics assembly 610 may include a singlelaser emitter that is configured to provide a narrow beam having awavelength of 905 nm. In other embodiments, the optics assembly 610 mayinclude multiple light sources similarly to the LIDAR device 200 ofFIGS. 2A-2C. As shown, the optics assembly 610 includes the transmitlens 652 for collimation and/or focusing of emitted light from theoptics assembly 610 onto the mirror 620, and a receive lens 654 forfocusing reflected light from the mirror 660 onto one or more detectors(not shown) of the optics assembly 610. However, in some examples, theoptics assembly 610 may alternatively include a single lens for bothcollimation of emitted light and focusing of reflected light similarlyto the lens 250 of the LIDAR device 200.

As shown, the mirror 660 may be arranged to steer emitted light from thetransmit lens 652 towards the viewing direction of the LIDAR device 600.Further, for example, the mirror 660 may be arranged to steer reflectedlight from the mirror 660 towards the receive lens 654. In someexamples, the mirror 6690 may be a triangular mirror that performscomplete rotations about an axis defined by the pin 662. In oneembodiment, the vertical FOV of the LIDAR device 600 is 110°.

The pin 662 may be configured to mount the mirror 660 to the LIDARdevice 600. In turn, the pin 662 can be formed from any material capableof supporting the mirror 660. For example, the pin 662 may be formedfrom a solid material such as plastic or metal among otherpossibilities. In some examples, the LIDAR device 600 may be configuredto rotate the mirror 660 about the pin 662 for complete rotations tosteer emitted light from the optics assembly 610 vertically. In otherexamples, the LIDAR device 600 may be configured to rotate the mirror660 about the pin 662 over a given range of angles to steer the emittedlight. Thus, in some examples, various vertical FOVs are possible byadjusting the rotation the mirror 660 about the pin 662.

The motor 670 may include any motor such as a stepper motor, an electricmotor, a combustion motor, a pancake motor, and/or a piezoelectricactuator among other possibilities. In some examples, the motor 670 maybe configured to rotate various components of the LIDAR device 600(e.g., optics assembly 610, mirror 660, pin 662, etc.) about an axis ofthe LIDAR device 600. For example, the axis may be substantiallyvertical similarly to the y-axis shown in FIG. 6A. By rotating thevarious components of the LIDAR device 600 about the axis, in someexamples, the motor 670 may steer the emitted light that is reflectedoff the mirror 660 horizontally, thus allowing the LIDAR device 600 tohave a horizontal FOV. In one embodiment, the motor 670 may rotate for adefined amount of rotation such as 270°. In this embodiment, the LIDARdevice 600 may thus have a horizontal FOV of 270. However, other amountsof rotation are possible as well (e.g., 360°, 8°, etc.) thereby allowinga different horizontal FOV for the LIDAR device 600. Thus, in someexamples, the LIDAR device 600 may provide an alternative device forscanning the environment or a portion thereof to the LIDAR device 104 ofFIG. 1, and/or the LIDAR device 200 of FIGS. 2A-2C.

FIG. 6B illustrates a partial cross-section view of the LIDAR device 600shown in FIG. 6A. It is noted that some of the components of the LIDARdevice 600 are omitted from the illustration of FIG. 6B for conveniencein description.

As shown, the optics assembly 610 comprises a transmit block 620 thatincludes one light source 622. In some examples, the transmit block 620may alternatively include more than one light source similarly to thetransmit block 220 of the LIDAR device 200. However, for the sake ofexample, the transmit block 620 includes one light source 622. The lightsource 622 may be configured to emit one or more light pulses (e.g.,laser beams, etc.) towards the transmit lens 652. For example, as shown,emitted light 602 a propagates away from the light source 622 towardsthe transmit lens 652. In some examples, the light source 622 may besimilar to the light sources 222 a-c of the LIDAR device 200 of FIGS.2A-2C. In one embodiment, the light source 622 may be configured to emitlight pulses having a wavelength of 905 nm. In other embodiments, thelight source 622 may be configured to emit light having any otherwavelength.

In line with the discussion above, the transmit lens 652 may beconfigured to collimate the emitted light 602 a into one or morecollimated light beams 602 b and/or may be configured to focus theemitted light 602 a as the focused light 602 b onto the mirror 660.

As shown, the mirror 660 may be a triangular mirror that has threereflective surfaces 660 a, 660 b, 660 c. However, in other examples, themirror 660 may alternatively include a greater or fewer number ofreflective surfaces. As shown, the collimated light 602 b may thenreflect off the reflective surface 602 a and into the environment of theLIDAR 600 as emitted light 602 c. For example, a direction of theemitted light 602 c is illustrated by arrow 604. In practice, as themirror 660 is rotated about an axis defined by the pin 662, the emittedlight 602 c may be steered to have a different direction than thatillustrated by arrow 604. For example, the direction 604 of the emittedlight 602 c may instead correspond to a different direction along arrow606. Thus, by rotating the mirror 660 about the pin 662, the LIDARdevice 600 may be configured to have a vertical FOV, for example.

Consider by way of example a scenario where the mirror 660 is configuredto rotate about an axis defined by the pin 662 continuously in aclock-wise direction. In this scenario, the direction 604 of the emittedlight 602 c may thereby be adjusted also in a clock-wise direction asillustrated by the arrow 606 until the focused light 602 b is reflectingoff an edge of the reflective surface 660 a. At this point, the emittedlight 602 c would be directed towards a maximum extent of the verticalFOV of the LIDAR device 600. Continuing with the scenario, as the mirror660 continues to rotate, the collimated light 602 b may then be focusedonto the reflective surface 660 b instead of the reflective surface 660a. At this point, the reflected light 602 c may be steered to adirection that is towards a minimum extent of the vertical FOV of theLIDAR device 600. Continuing with the scenario, as the mirror 660continues to rotate, the direction of the emitted light 602 c may thenbe adjusted in a clock-wise direction towards the maximum extent of thevertical FOV that corresponds to the light 602 b being focused ontoanother edge of the reflective surface 660 b. Similarly, continuing withthe scenario, the direction of the emitted light 602 c may then beadjusted to scan the vertical FOV of the LIDAR device 600 by reflectingthe light 602 b off the reflective surface 660 c instead of thereflective surface 660 b. Through this process, for example, the LIDARdevice 600 may continuously scan the vertical FOV. As a variation of thescenario above by way of example, the mirror 660 may be alternativelyconfigured to rotate within a given range of angles (e.g., wobble, etc.)to define a narrower vertical field-of-view than that of the scenariodescribed above. Other configurations for rotation of the mirror 660 arepossible as well.

FIG. 6C illustrates a partial cross-section view of the optics assembly610 in the LIDAR device 600 of FIG. 6A. For purposes of illustration,FIG. 6C shows an x-y-z axis, in which the z-axis is pointing out of thepage, and the x-axis and y-axis define a horizontal plane along thesurface of the page.

As shown, the optical assembly 610 comprises transmit block 620 thatincludes one light source 622. The light source 622 may be similar tothe light sources 222 a-c of the LIDAR device 200. In line with thediscussion above, in some examples, the transmit block 620 mayalternatively include more than one light source. The light source 622is configured to emit light 602 a toward the transmit lens 652. Further,the optical assembly 610 comprises receive block 630 that includes onedetector 632. The detector 632 may be similar to the detectors 232 a-cof the LIDAR device 200. Again, in some examples, the receive block 630may alternatively include more than one detector. The detector 632 maybe configured to receive light 608 focused by the receive lens 654.

As shown, the optics assembly 610 also includes an optical shield 612.The optical shield 612 may be configured to provide optical shieldingbetween the transmit block 620 and the receive block 630, at least forthe light having the source wavelength of the emitted light 602 a. Inturn, the optical shield 612 may mitigate interference with light 608detected by the detector 632 of the receive block 630. The opticalshield 612 may be formed, for example, as a wall coated by a metal,metallic ink, or metallic foam to provide the shielding. Example metalsmay include copper or nickel. Other configurations and/or materials arepossible as well for the optical shield 612.

As noted in the description of the system 100 of FIG. 1, in someexamples, the present method allows alignment of the detector 632 withlight originating at the light source 622. By way of example, analignment apparatus (e.g., apparatus 160) may couple to the transmitblock 620 and/or the receive block 630, and may then adjust the relativeposition between the transmit block 620 and the receive block 630 toperform the alignment.

The optical components (i.e., the transmit block 620 and the receiveblock 630) of the optical assembly 610 may each have six degrees offreedom (DOF). Three of the six DOF are translational: forward/backward(e.g., linearly along an axis of the optical component that is parallelto the y-axis shown in FIG. 6C), up/down (e.g., linearly along an axisof the optical component that is parallel to the z-axis), and left/right(e.g., linearly along an axis of the optical component that is parallelto the x-axis). Further, three of the six DOF are rotational: pitch(e.g., rotation about the axis of the optical component that is parallelto the x-axis), yaw (e.g., rotation about the axis of the opticalcomponent that is parallel to the z-axis), and roll (e.g., rotationabout the axis of the optical component that is parallel to the y-axis).In accordance with the present disclosure, the alignment apparatus (notshown) may adjust the relative position between the transmit block 620and the receive block 630 shown in FIG. 6C by adjusting some or all ofthe six DOF described above for one or both of the transmit block 620and the receive block 630.

In line with the discussion above, systems and methods herein allowoptics alignment for LIDAR devices having various differentconfigurations. Thus, the configurations of the LIDAR devices 200 and600 are presented for exemplary purposes only. Other configurations andLIDAR devices are possible as well for the systems and methods herein.

FIG. 7A illustrates a system 700, according to an example embodiment.The system 700 may be similar to the system 100 of FIG. 1. For example,as shown, the system 700 includes a mounting platform 702, a LIDARdevice 704, a camera 706, a light filter 708, and an alignment apparatus760 that can be similar, respectively, to the mounting platform 102, theLIDAR device 104, the camera 106, the light filter 108, and thealignment apparatus 160 of the system 100. As shown, the system 700 alsoincludes a mounting structure 710, an actuator 712, and a manipulator762.

The mounting structure 710 may be formed from any solid material (e.g.,metal, plastic, etc.) similarly to the mounting platform 702, and may beshaped to facilitate coupling one or more of the components of thesystem 700 to the mounting platform 702. As shown, for example, themounting structure 710 couples the camera 706 and the light filter 708to the mounting platform 702. However, in some examples, a separatemounting structure may be utilized for each of the camera 706 and thelight filter 708.

The actuator 712 may be configured to adjust a position of the lightfilter 708. Example actuators may include motors, stepper motors,pneumatic actuators, hydraulic pistons, relays, solenoids, andpiezoelectric actuators among other possibilities.

The manipulator 762 may include any structure configured to couple thealignment apparatus 702 with one or more components of the LIDAR device704. In line with the discussion above, the system 700 may adjust arelative position between a transmit block (not shown) and a receiveblock (not shown) of the LIDAR device 704. For instance, the alignmentapparatus 760 (e.g., robotic arm, etc.) may adjust the relative positionbetween the transmit block and the receive block by adjusting theposition of the manipulator 762 or changing the orientation of themanipulator 762, among other possibilities.

As shown, the mounting platform 702 includes a plurality of holes,exemplified by holes 702 a and 702 b. In some embodiments, the variouscomponents such as the LIDAR device 704, the camera 706, and/or thelight filter 708 may be mounted to the mounting platform by coupling thevarious components to such holes in the mounting platform (e.g., byfastening a bolt through the holes). In other embodiments, the variouscomponents may be mounted to the mounting platform 702 via otherprocesses or devices. In one example, the various components may bemounted to the mounting platform 702 via an application of an adhesiveamong other possibilities. In another example, a mounting structure maycouple one or more of the components to the mounting platform 702. Forinstance, as shown in FIG. 7A, the mounting structure 710 may be coupledto the mounting platform 702 (e.g., by fastening a bolt to one of theholes, etc.), and may also be coupled the camera 706 and the lightfilter 708 to provide the particular positions of the camera 706 and thelight filter 708 relative to the mounting platform 702. Otherconfigurations and shapes of the mounting structure 710 are possible aswell.

Further, as shown, the LIDAR device 704 has a configuration similar tothe LIDAR device 200 of FIGS. 2A-2C. However, in some examples, otherconfigurations are possible for the LIDAR device 704, such as theconfiguration of the LIDAR device 600 of FIGS. 6A-6C among otherpossibilities.

An example scenario for operation of the system 700 is as follows.First, as shown, the LIDAR device 704 may be mounted to the mountingplatform 702 to have a field-of-view (FOV) through which light emittedby a transmit block (not shown) of the LIDAR device 704 and lightreceived by a receive block (not shown) of the LIDAR device 704propagates. For instance, the LIDAR device 704 may be mounted to themounting platform 702 using the alignment apparatus 760 (e.g., roboticarm, etc.) or any other device (e.g., mechanical tool, etc.). Next, thecamera 706 may be located at a given position relative to the LIDARdevice 704 such that the camera 706 may obtain images of the receiveblock (not shown) of the LIDAR device 704 and/or light emitted by thetransmit block (not shown) of the LIDAR device 704.

Continuing with the scenario, the camera 706 may then be focused toinfinity for the source wavelength (e.g., 905 nm) of the light emittedby the LIDAR device 704. Next, the light filter 708 may be positioned ata first position to be interposed between the LIDAR device 704 and thecamera 706 along the FOV of the LIDAR device 704. For instance, theactuator 712 may be configured to move the light filter 708 to the firstposition shown in FIG. 7A.

Continuing with the scenario, the system 700 may then cause the transmitblock (not shown) of the LIDAR device 704 to emit one or more lightbeams through the light filter 708 and toward the camera 706. Referringback to FIG. 2B by way of example, the light beams may correspond to thelight beams 204 a-c propagating out of the lens 250. Next, the camera706 may obtain a first image of the light beams emitted by the LIDARdevice 704. Continuing with the example of FIG. 2B, the first image mayindicate light source positions of light sources 222 a-c in the LIDARdevice 200. At this point in the scenario, the system may then cause theLIDAR device 704 to stop emitting the light beams.

Continuing with the scenario, the system may then cause the actuator 712to move the light filter 708 to a second position where the light filter708 is not interposed between the camera 706 and the LIDAR 704. FIG. 7Billustrates the light filter 708 at the second position described above.In turn, the camera 706 may obtain a second image. The second image mayindicate detector positions of detectors in a receive block (not shown)of the LIDAR device 704. Referring back to FIG. 2B by way of example,the second image may represent the detector positions of detectors 232a-c that are viewable to the camera 706 via mirror 242 and lens 250.

Continuing with the scenario, the system 700 may then determine at leastone offset based on the first image and the second image. In oneinstance, the at least one offset may include distances between adjacentlight sources and/or adjacent detectors of the LIDAR device 704. Inanother instance, the at least one offset may include distances betweenlight beams emitted by light sources in the LIDAR device 704 andcorresponding detectors of the LIDAR device 704. Other offsets arepossible as well and are described in greater detail within exemplaryembodiments herein.

In line with the discussion above, the alignment apparatus 760 (e.g.,robotic arm, etc.) may couple to the transmit block (not shown) and/orthe receive block (not shown) of the LIDAR device 704 via themanipulator 762. Thus, in the scenario, the alignment apparatus 760 maythen adjust the relative position between the transmit block and thereceive block in accordance with the determined at least one or moreoffset.

FIG. 7C illustrates a partial view of the system 700 shown in FIGS.7A-7B. It is noted that some of the components of the system 700 areomitted from the illustration of FIG. 7C for convenience in description.For purposes of illustration, FIG. 7C shows an x-y-z axis, in which thez-axis is pointing out of the page, and the x-axis and y-axis define ahorizontal plane along the surface of the page.

As shown in FIG. 7C, the manipulator 762 includes protrusions 762 a-dthat may be configured to couple with receive block 730. The receiveblock 730 may be included in the LIDAR device 704 shown in FIGS. 7A-7B.It is noted that other components of the LIDAR device 704 (e.g.,transmit block, etc.) are omitted from the illustration of FIG. 7C forconvenience in description. The receive block 730 may be similar to thereceive block 230 of the system 200. However, in some embodiments, thereceive block 730 may take any other form such as the configuration ofthe receive block 630 among other possibilities.

Similarly to the description of the receive block 630 of FIG. 6C, thereceive block 730 has six degrees of freedom (DOF). Three of the six DOFare translational: forward/backward (e.g., linearly along an axis of thereceive block 730 that is parallel to the z-axis shown in FIG. 7C),up/down (e.g., linearly along an axis of the receive block 730 that isparallel to the y-axis), and left/right (e.g., linearly along an axis ofthe receive block 730 that is parallel to the x-axis). Further, three ofthe six DOF are rotational: pitch (e.g., rotation about the axis of thereceive block 730 that is parallel to the x-axis), yaw (e.g., rotationabout the axis of the optical component that is parallel to the y-axis),and roll (e.g., rotation about the axis of the optical component that isparallel to the z-axis).

Continuing with the scenario, the system 700 may adjust the position ofthe receive block 730, when coupled to the manipulator 762, by adjustingthe forward/backward position, the up/down position, the left/rightposition, the pitch, the yaw, and/or the roll of the receive block 730in line with the discussion above. In turn, the system 700 may adjustthe relative position between the transmit block (not shown) of theLIDAR 704 and the receive block 730. In some embodiments, additionallyor alternatively to the adjustments to the position/orientation of thereceive block 730, the manipulator 762 may adjust theposition/orientation of the transmit block (not shown) of the LIDARdevice 704 in a similar manner. Through this process, for example, thesystem 700 may align one or more light sources of the LIDAR device 704with one or more detectors of the LIDAR device 704.

In some embodiments, the system 700 may then decouple the manipulator762 from the receive block 730 (or the transmit block), and the receiveblock 730 may be configured to remain at the alignment (e.g., relativeposition) performed by the alignment apparatus 760. By way of example,the system 700 may apply an epoxy or other adhesive to a periphery ofthe receive block 730 to maintain the receive block 730 at the alignedrelative position to the transmit block of the LIDAR device 704. In oneinstance, the manipulator 762 may remain coupled to the receive block730 until the adhesive is cured. However, other processes are possibleas well for maintaining the relative position between the transmit blockand the receive block 730 of the LIDAR device 704. For instance, thereceive block 730 may be fastened to a housing of the LIDAR device 704using bolts, screws, or any other device among other possibilities.

It is noted that the scenario presented above is for exemplary purposesonly. Other scenarios are possible as well that may include some or allof the components of the system 700, or may include other processes thanthose described. A non-exhaustive list of example variations of thescenario is presented below.

In a first example, the system 700 may not include the light filter 708.For instance, the camera 706 may be configured to obtain the first imageand the second image without the light filter 708 being interposedbetween the camera 706 and the LIDAR device 704.

In a second example, the camera 706 and the light filter 708 may bemounted separately from the LIDAR device 704. For instance, the system700 may be implemented in an assembly line where multiple LIDAR devicessuch as the LIDAR device 704 are located on an assembly belt. In thisinstance, the camera 706, the light filter 708 and the robotic arm 760may be mounted independently adjacent to the assembly belt, and mayperform similar functions to the scenario described above to calibrateeach LIDAR device in the assembly line.

In a third example, the receive block 730 may be illuminated by anauxiliary light source (not shown) similar to the auxiliary light source170. For instance, the light filter 708 may remain interposed betweenthe LIDAR device 704 and the camera 706 while the first image of thelaser beams emitted by the LIDAR device 704 is captured by the camera706, and while the second image of the receive block 730 is captured aswell. In this instance, the receive block 730 would be visible to thecamera 706 through the light filter 708 due to the illumination by theauxiliary light source with light at the source wavelength that isviewable through the light filter 708.

In a fourth example, the LIDAR device 704 may be configured to continueemitting light while the camera 106 captures the first image and thesecond image. For instance, the light filter 708 may alternativelyattenuate the light beams having the source wavelength emitted by lightsources of the LIDAR device 704. Thus, in this instance, the lightfilter 708 may be positioned as shown in FIG. 7B while the camera 706 iscapturing the first image indicative of the light source positions.Further, in this instance, the light filter 708 may be positioned asshown in FIG. 7A while the camera 706 is capturing the second imageindicative of the detector positions. Thus, various configurations ofthe light filter 708 may therefore affect the operation of the system700 in line with the discussion above.

In a fifth example, the camera 706 may be configured to capture a singleimage instead of the first image and the second image. The single imagemay be indicative of both the light source positions of light sources inthe LIDAR device 704, and the detector positions of detectors in thereceive block 730. Referring back to FIG. 2B by way of example, thesingle image may capture both the light beams 204 a-c and lightreflected off the detectors 232 a-c. As in the third example above, thereceive block 730 in this example may be illuminated by an auxiliarylight source such that the detectors 232 a-c are viewable through thelight filter 708. Other example scenarios are possible as well.

FIG. 8 illustrates another system 800, according to an exampleembodiment. The system 800 may be similar to the systems 100 and 700.For example, the system 800 includes a mounting platform 802, a camera806, a light filter 808, and an alignment apparatus 860 that aresimilar, respectively, to the mounting platform 702, the camera 706, thelight filter 708, and the alignment apparatus 760 of the system 700. Thesystem 800 also includes a LIDAR device 804 that is similar to the LIDARdevice 104 of the system 100. The system 800 also includes a manipulator862 shaped and configured to couple the alignment apparatus 860 with oneor more components of the LIDAR device 804. The system 800 also includesan auxiliary light source 870 that is similar to the auxiliary lightsource 170 of the system 100.

As shown, the LIDAR device 804 has a configuration similar to the LIDARdevice 600 of FIGS. 6A-6C. However, in some examples, otherconfigurations are possible as well, such as the configuration of theLIDAR device 200 among other possibilities.

As shown, the light filter 808 is interposed between the LIDAR device804 and the camera 806. Additionally, the camera 806 is located at agiven position at which the camera 806 can image light beam(s) emittedby the LIDAR device 804 and can image detector(s) (not shown) in theLIDAR device 804. Referring back to FIG. 6A by way of example, thecamera 806 may be positioned to have a field-of-view facing the mirror660 of the LIDAR device 600.

However, as shown, the system 800 does not include an actuator (e.g.,actuator 712 of system 700) to move the light filter 808. Instead, thesystem 800 includes the auxiliary light source 870 to illuminate areceive block (not shown) of the LIDAR device 804 with light having thesource wavelength of light emitted by light source(s) (not shown) in theLIDAR device 804. For instance, such illumination may allow detectors inthe receive block of the LIDAR device 804 to be viewable by the camera806 through the light filter 808. Although the auxiliary light source870 is shown to be mounted separately from other components of thesystem 800, in some examples, the auxiliary light source 870 may bealternatively mounted to any of the components of the system 800, suchas the alignment apparatus 860, the light filter 808, the mountingplatform 802, etc. In one example, the auxiliary light source 870 may bealternatively mounted inside the LIDAR device 804. Referring back toFIG. 6C by way of example, the auxiliary light source may bealternatively mounted to a wall of the optics assembly 610. Otherconfigurations of the auxiliary light source 870 are possible as well.

As shown, the manipulator 862 has a different shape and structure thanthe manipulator 762 of the system 700. Referring back to FIG. 6C by wayof example, the manipulator 862 may have any shape suitable foradjusting position/orientation of the transmit block 620 and/or thereceive block 630.

Thus, in some examples, the system 800 may perform similar functions asthose described for the system 100 and the system 700, but may includesome variations suitable for other LIDAR device configurations, such asthe configuration of the LIDAR device 804.

FIG. 9 is a flowchart of a method 900, according to an exampleembodiment. Method 900 shown in FIG. 9 presents an embodiment of amethod that could be used with any of the systems 100, 700, 800, theLIDAR devices 200, 600, the transmit block 320, the light source 400,and/or the receive block 530, for example. Method 900 may include one ormore operations, functions, or actions as illustrated by one or more ofblocks 902-912. Although the blocks are illustrated in a sequentialorder, these blocks may in some instances be performed in parallel,and/or in a different order than those described herein. Also, thevarious blocks may be combined into fewer blocks, divided intoadditional blocks, and/or removed based upon the desired implementation.

In addition, for the method 900 and other processes and methodsdisclosed herein, the flowchart shows functionality and operation of onepossible implementation of present embodiments. In this regard, eachblock may represent a module, a segment, a portion of a manufacturing oroperation process, or a portion of program code, which includes one ormore instructions executable by a processor for implementing specificlogical functions or steps in the process. The program code may bestored on any type of computer readable medium, for example, such as astorage device including a disk or hard drive. The computer readablemedium may include non-transitory computer readable medium, for example,such as computer-readable media that stores data for short periods oftime like register memory, processor cache and Random Access Memory(RAM). The computer readable medium may also include non-transitorymedia, such as secondary or persistent long term storage, like read onlymemory (ROM), optical or magnetic disks, compact-disc read only memory(CD-ROM), for example. The computer readable media may also be any othervolatile or non-volatile storage systems. The computer readable mediummay be considered a computer readable storage medium, for example, or atangible storage device.

In addition, for the method 900 and other processes and methodsdisclosed herein, each block in FIG. 9 may represent circuitry that iswired to perform the specific logical functions in the process.

At block 902, the method 900 involves mounting a transmit block and areceive block in a light detection and ranging (LIDAR) device to providea relative position between the transmit block and the receive block.The transmit block may include one or more light sources configured toemit light at a source wavelength. The receive block may include one ormore detectors configured to detect light at the source wavelength. Inone embodiment, the source wavelength is 905 nm. In other embodiments,the source wavelength may be any other wavelength (e.g., infrared,ultraviolet, x-ray, visible, etc.).

By way of example, the transmit block and the receive block may bemounted by a robotic arm (e.g., alignment apparatuses 160, 760, 860,etc.) into a housing (e.g., housing 210, optics assembly 610, etc.) toprovide the relative position. In this example, the relative positionmay be similar to the relative position between transmit block 220 andreceive block 230 of FIG. 2B, or the relative position between transmitblock 620 and receive block 630 of FIG. 6C, among other possibilities.However, in other examples, the mounting at block 902 may be performedby a device other than the alignment apparatus. For instance, themounting at block 902 may correspond to an alignment (e.g., adjustmentof the relative position) by a system performing the method 900 for atransmit block and a receive block that are already mounted in a LIDARdevice.

In some examples, the LIDAR device may include a lens configured to (i)collimate light emitted from the one or more light sources and (ii)focus light onto the one or more detectors, similarly to the lens 250 ofthe LIDAR device 200. In other examples, the LIDAR device may include atransmit lens for collimation of emitted light and a receive lens forfocusing received light, similarly to the transmit lens 652 and thereceive lens 654 of the LIDAR device 600.

At block 904, the method 900 involves locating a camera at a givenposition at which the camera, when focused at infinity, can image lightbeams emitted by the one or more light sources and can image the one ormore detectors. By way of example, the given position may be similar tothe position of the camera 706 of the system 700. For instance, afield-of-view of the camera may be aligned with a FOV of the LIDARdevice where light emitted from the one or more light sources propagatesaway from the LIDAR device.

At block 906, the method 900 involves obtaining a first image indicativeof light source positions of the one or more light sources. The firstimage, for example, may be obtained using the camera located at thegiven position and focused at infinity. Referring back to FIG. 2B by wayof example, the light source positions of the light sources 222 a-c mayvary according to the particular orientation and position of thetransmit block 220. In turn, the direction of propagation of the lightbeams 204 a-c may also vary, and such variation may be represented bypixels in the first image obtained by the camera.

In some examples, the method 900 may also involve obtaining the firstimage while the one or more light sources are emitting light at thesource wavelength. For instance, a system performing the method 900 mayprovide power and/or instructions to the LIDAR device to emit the lightat the source wavelength, and may provide instructions to the camera tocapture the first image while the one or more light sources are emittingthe light. Further, in some instances, the system may provideinstructions to the camera to adjust the focus to infinity for thesource wavelength. Alternatively, for instance, the camera may beconfigured to have the focus prior to capturing the first image.

In some examples, the method 900 may also involve obtaining the firstimage while a light filter is interposed between the camera and the oneor more light sources. The light filter may be similar to the lightfilters 108, 708, or 808. In one example, the light filter may beconfigured to attenuate light having wavelengths other than the sourcewavelength. In this example, the first image may be more suitable forrepresenting features of the emitted light beams at the sourcewavelength. In another example, the light filter may be configured toattenuate light within a wavelength range that includes the sourcewavelength. In this example, the light filter may reduce the intensityof the emitted light to protect components of the camera. Additionallyor alternatively, in this example, the light filter may reduce an amountof light propagating toward the camera that has wavelengths proximal tothe source wavelength. In turn, for instance, pixels in the first imagerepresenting the emitted light beams having the source wavelength may beeasily contrasted from surrounding pixels having proximal wavelengths.

In some examples, the method 900 may also involve detecting a defect ina light source based on the first image. In one example, the first imagemay indicate that one or more of the light sources in the transmit blockhas a different intensity, brightness, color, or other characteristiccompared to other light sources. For instance, a system performingmethod 900 may compare pixel properties (e.g., brightness, intensity,color, etc.) associated with one light source against other pixelproperties in the first image associated with another light source.Alternatively, for instance, the system may compare the pixel propertiesof the light source with pre-determined pixel properties or pixelproperties in a stored image among other possibilities.

In some examples, the method 900 may also involve detecting anaberration in an optical element optically coupled to a light sourcebased on the first image. Referring back to FIGS. 4A-4C by way ofexample, the light source may be coupled to an optical element such asthe cylindrical lens 404. In this example, the system performing themethod 900 may detect the aberration in such optical element byexamining the shape or other properties of pixels in the first imagethat are associated with a light beam from the light source (e.g.,compare with other pixels, compare with stored parameters/image, etc.).Thus, in some embodiments, the method 900 may allow diagnosis of lightsource(s) in the LIDAR device.

At block 908, the method 900 involves obtaining a second imageindicative of detector positions of the one or more detectors. Similarlyto the first image, the second image may be obtained using the cameralocated at the given position and focused at infinity. Referring back toFIG. 2B by way of example, the second image may represent the detectors232 a-c that are viewable to the camera via the lens 250 and the mirror242. Referring back to FIGS. 6A-6C as another example, the second imagemay represent the detector 632 that is viewable to the camera via thelens 654 and the mirror 660. Thus, in some embodiments, the camera mayobtain the first image and the second image while the camera is locatedat the same given position.

In some examples, the method 900 may also involve obtaining the secondimage while the one or more light sources are not emitting light at thesource wavelength. For instance, a system performing the method 900 mayreduce power to the one or more light sources and/or provideinstructions to the LIDAR device to stop emitting light beams.

However, in other examples, the method 900 may involve obtaining thesecond image while the one or more light sources are emitting the lightat the source wavelength. In one instance, a light filter may beinterposed between the camera and the LIDAR device while the camera iscapturing the second image, and the light filter may be configured toattenuate light at the source wavelength emitted by the one or morelight sources. In this instance, the system performing the method 900may then obtain the second image indicative of the detector positionswhile the light filter attenuates the light beams emitted by the one ormore light sources. In another instance, the second image may indicateboth the light source positions and the detector positions since the oneor more light sources are emitting the light at the source wavelengthwhen the second image is obtained. Other examples are possible as well.

In some examples, the method 900 may also involve obtaining the secondimage while the one or more detectors are illuminated with light at thesource wavelength from an auxiliary light source. The auxiliary lightsource may be similar to the auxiliary light sources 170 and 870included, respectively, in the systems 100 and 800. In one example, thecamera may be focused at infinity for the source wavelength. In anotherexample, a light filter interposed between the camera and the LIDARdevice may be configured to attenuate light having wavelengths otherthan the source wavelength. In both examples, the auxiliary light sourcemay illuminate the one or more detectors such that reflections of theilluminating light having the source wavelength are viewable by thecamera when capturing the second image.

At block 910, the method 900 involves determining at least one offsetbased on the light source positions indicated by the first image and thedetector positions indicated by the second image. In one example, the atleast one offset may include distances between adjacent regions of thefirst image that are associated with particular light sources. Inanother example, the at least one offset may include distances betweenadjacent regions of the second image that are associated with particulardetectors. In yet another example, the at least one offset may includean offset between a region of the first image associated with a givenlight source, and a corresponding region of the second image associatedwith a given detector. The offset in the third example may have ahorizontal component and a vertical component, or may just be a distancebetween the respective regions (e.g., number of pixels). As a variationof the third example, the offset may also include a depth componentwhere the camera is configured to obtain 3D images, for instance. Otheroffsets are possible as well.

In some examples, the method 900 may also involve generating a compositeimage based on overlaying the first image and the second image. In theseexamples, the at least one offset may be determined based on separationbetween one or more pixels in the composite image associated with alight source and one or more pixels in the composite image associatedwith a corresponding detector.

At block 912, the method 900 includes adjusting a relative positionbetween the transmit block and the receive block based at least in parton the at least one offset. By way of example, a robotic arm or otherdevice (e.g., alignment apparatuses 160, 760, 860, etc.) may couple tothe transmit block and/or the receive block to adjust the relativeposition. The robotic arm, for instance, may translate the coupledcomponent linearly and/or rotate the coupled component about an axis inline with the discussion for the systems 100, 700, and 800.

Accordingly, in some examples, the method 900 may also involve adjustingthe relative position between the transmit block and the receive blockby rotating the receive block about an axis. Further, in some examples,the method 900 may also involve adjusting the relative position byrotating the transmit block about an axis.

In some examples, adjusting the relative position between the transmitblock and the receive block at block 912 reduces the at least oneoffset. For instance, where the at least one offset includes an offsetbetween a light source and a corresponding detector, the adjustment ofthe relative position may reduce the offset to align the light sourcewith the detector. In other examples, adjusting the relative positionbetween the transmit block and the receive block at 912 causes the atleast one offset to correspond to a particular offset. For instance,where the at least one offset includes an offset between two adjacentlight sources, the adjustment of the relative position may cause theoffset to correspond to the particular offset.

FIG. 10 illustrates an image 1000 indicative of light source positionsof light sources in a transmit block of a LIDAR device, according to anexample embodiment. The image 1000 may be similar to the first imagedescribed at block 906 of the method 900. For instance, dark pixels inthe image 1000 may represent light beams emitted by one or more lightsources in a transmit block. Referring back to FIG. 3 by way of example,each of regions 1002, 1004, 1006 in the image 1000 may correspond,respectively, to light beams 302 a, 302 b, 302 c emitted by lightsources 322 a, 322 b, 322 c of the transmit block 320.

FIG. 11 illustrates an image 1100 indicative of detector positions ofdetectors in a receive block, according to an example embodiment. Theimage 1100 may be similar to the second image described at block 908 ofthe method 900. Referring back to FIG. 5A by way of example, regions1102, 1104, 1106 in the image 1100 may correspond, respectively, to thedetectors 532 a, 532 b, 532 c of the receive block 530.

FIG. 12 illustrates an image 1200 in a scenario where light sources in atransmit block and detectors in a receive block of a LIDAR device arealigned, according to an example embodiment. For example, the image 1200may correspond to a composite image generated by overlaying the image1000 and the image 1100, in line with the discussion at block 910 of themethod 900.

However, in some examples, light sources and detectors in a LIDAR devicemay not be aligned with one another due to manufacturing/assemblyvariability or other factors.

FIG. 13 illustrates an image 1300 in a scenario where the light sourcesand the detectors of a LIDAR device are misaligned along the up/down DOFdescribed in the discussion of FIG. 7C, according to an exampleembodiment. Image 1300 may be a composite image determined similarly tothe image 1200. For instance, region 1302 may correspond to region 1006of the image 1000, and region 1304 may correspond to region 1106 of theimage 1100. In turn, the at least one offset determined at block 910 ofthe method 900 may correspond to a distance (e.g., pixel distance, etc.)between the region 1302 and the region 1304, and a system (e.g., system700, etc.) may perform the adjustment of the relative position betweenthe transmit block and the receive block to align the light sourceassociated with region 1302 with the detector associated with region1304. By way of example, the system may adjust the up/down position ofthe transmit block and/or the up/down position of the receive block toreduce the determined offset, in line with the discussion above.

FIG. 14 illustrates an image 1400 in a scenario where the light sourcesand the detectors of the LIDAR device are misaligned along theleft/right DOF described in the discussion of FIG. 7C, according to anexample embodiment. As a variation of the discussion for image 1300, anoffset in the LIDAR device of image 1400 may correspond to the distancebetween the regions 1402 (e.g., associated with a light source) and 1404(e.g., associated with a corresponding detector).

FIG. 15 illustrates an image 1500 in a scenario where the light sourcesand the detectors are misaligned along the forward/backward DOF,according to an example embodiment. For instance, as shown in image1500, the regions that correspond to light source positions appearsmaller and closer to one another, than the regions that correspond todetector positions. Similarly here, one or more offsets according toblock 910 of the method 900 may be determined. An example offset may bea ratio between: (i) the distance between region 1502 and 1504 (e.g.,particular detector positions), and (ii) the distance between regions1506 and 1508 (e.g., corresponding light source positions). However,other offsets are possible as well such as offsets determined by variousimage processing algorithms to detect differences in sizing or depthamong other possibilities.

FIG. 16 illustrates an image 1600 in a scenario where the light sourcesand the detectors are misaligned along the roll DOF described in FIG.7C, according to an example embodiment. Similarly here, the offsetbetween the roll position of the light sources and the roll position ofthe detectors may be determined. For instance, an image processingalgorithm may determine such offset, and a system of the present methodmay adjust the relative position between the transmit block and thereceive block accordingly. Alternatively, for instance, manual operationof a robotic arm may be employed by visual inspection of the image 1600(e.g., video feed, etc.) to adjust the relative position between thetransmit block and the receive block, among other possibilities.

FIG. 17 illustrates an image 1700 in a scenario where the light sourcesand detectors are misaligned along the yaw DOF described in FIG. 7C,according to an example embodiment. For instance, as shown, light beamsfrom light sources at a right side of the image 1700 (e.g., associatedwith regions 1702 and 1704) are at a greater distance (e.g., offset) toone another than light sources at a left side of the image 1700 (e.g.,associated with regions 1706 and 1708). This variation may be due to theyaw of the transmit block. In contrast, distances between adjacentcorresponding detectors (e.g., associated with regions 1710 and 1712) donot exhibit the same variation, due to the receive block having adifferent yaw. Thus, in some examples, the present method may adjust theyaw of the receive block to correspond to the yaw of the transmit block.Alternatively or additionally, in some examples, the present method mayadjust the yaw of the transmit block to correspond to the yaw of thereceive block.

FIG. 18 illustrates an image 1800 in a scenario where the light sourcesand detectors are misaligned along the pitch DOF described in FIG. 7C,according to an example embodiment. Similarly to the discussion abovefor the yaw misalignment in image 1700, the transmit block in thisscenario has a pitch orientation that is different from the pitchorientation of the receive block. For instance, a distance (e.g.,offset) between light beams indicated by regions 1802 and 1804 isdifferent from the distance between light beams indicated by regions1806 and 1808, due to the pitch of the transmit block. Further,corresponding detectors for those light beams are not similarlyseparated in the image 1800, which indicates that the receive block hasa different pitch than the pitch of the transmit block. In turn,similarly to the discussion above for image 1700, the present method mayadjust the pitch of the transmit block, the receive block, or both, toalign the transmit block with the receive block, in line with thediscussion at block 912 of the method 900.

Although images 1200-1800 illustrate composite images overlaying a firstimage (e.g., image 1000, etc.) with a second image (e.g., image 1100),in some examples, the present method may determine the various offsetsdescribed above for images 1200-1800 without overlaying the two images.For instance, a computing device herein may determine the variousoffsets by comparing pixel locations in the first image 1000 withcorresponding pixel locations in the second image 1100. Other imageprocessing techniques are possible as well (e.g., filtering, transforms,etc.) for determining the at least one offset described at block 910 ofthe method 900.

Further, although images 1300-1800 illustrate scenarios where the lightsources and the detectors are offset in only one DOF, in some examples,the light sources and the detectors may be offset in more than one DOF.For instance, a LIDAR device may have light sources and detectors thatare offset in both the forward/backward DOF described in image 1500 andthe roll DOF described in image 1600. Other offset combinations arepossible as well.

Further, although images 1000-1800 represent light sources and detectorsof a LIDAR device having a similar configuration to the LIDAR device200, in some examples, similar images may be generated for any otherLIDAR device configuration, such as the configuration of the LIDARdevice 600 among other possibilities.

In addition to alignment of light sources and detectors of a LIDARdevice, in some examples, the present method may facilitate diagnosis ofthe various components of the LIDAR device. As an example, FIG. 19illustrates an image 1900 indicative of a defect or an aberration. Image1900 is an example image of light beams from a transmit block, similarlyto the image 1000. For instance, region 1902 of image 1900 maycorrespond to a light beam from a light source, similarly to region 1002of the image 1000. In one example, region 1904 may represent a lightbeam from a defective light source. For instance, pixels in region 1904may have a different color, brightness, intensity, or any othercharacteristic than pixels in other similar regions (e.g., region 1902),due to a defect in the light source associated with region 1904. Inanother example, region 1906 may be a region where a light beam from alight source is expected, and therefore the associated light source mayalso be defective. In yet another example, regions 1908 and 1910 appeardistorted compared to similar regions (e.g., region 1902). In turn, forinstance, such distortions may indicate that optical elements (e.g.,cylindrical lens 404 of FIGS. 4B-4C, etc.) coupled to light sourcesassociated with regions 1908 and 1910 may have aberrations, and thepresent method may therefore detect the aberrations. Other exampledefects and aberrations are possible as well. In some examples, thepresent method may detect the various defects/aberrations describedabove by comparing the various regions 1904-1910 with similar regions inthe image 1900 (e.g., region 1902, etc.). Additionally or alternatively,in some examples, the present method may detect the variousdefects/aberrations by comparing the image 1900 with a stored image(e.g., image 1000).

FIG. 20 is a flowchart of another method 2000, according to an exampleembodiment. Method 2000 shown in FIG. 20 presents an embodiment of amethod that could be used with any of the systems 100, 700, 800, theLIDAR devices 104, 200, 600, 704, 804, the transmit block 320, the lightsource 400, and/or the receive block 530, for example. Method 2000 mayinclude one or more operations, functions, or actions as illustrated byone or more of blocks 2002-2004. Although the blocks are illustrated ina sequential order, these blocks may in some instances be performed inparallel, and/or in a different order than those described herein. Also,the various blocks may be combined into fewer blocks, divided intoadditional blocks, and/or removed based upon the desired implementation.

At block 2002, the method 2000 involves obtaining one or more imagesusing a camera located at a given position at which the camera can imagelight beams emitted by one or more light sources in a transmit block ofa LIDAR device and can image one or more detectors in a receive block ofthe LIDAR device. In some examples, the one or more images may include asingle image that indicates both light source positions of the one ormore light sources and detector positions of the one or more detectors.For instance, the single image may be similar to images 1200-1800 shownin FIGS. 12-18. In other examples, the one or more images may include afirst image indicative of the light source positions and a second imageindicative of the detector positions, similarly to the first image andthe second image described, respectively, at blocks 906 and 908 of themethod 900.

In some examples, the method 2000 may also involve causing an actuatorto move a light filter to a first position where the light filter isinterposed between the camera and the LIDAR device, obtaining a firstimage indicative of light source positions of the one or more lightsources while the light filter is at the first position, causing theactuator to move the light filter to a second position where the lightfilter is outside a field-of-view of the camera, and obtaining a secondimage indicative of detector positions of the one or more detectorswhile the light filter is at the second position. Referring back toFIGS. 7A and 7B by way of example, the actuator, the light filter, andthe camera may correspond, respectively, to the actuator 712, the lightfilter 708, and the camera 706. Thus, in this example, the method 2000may adjust the position of the light filter 708 to the first positionillustrated in FIG. 7A to obtain the first image, and to the secondposition illustrated in FIG. 7B to obtain the second image.

At block 2004, the method 2000 involves adjusting a relative positionbetween the transmit block and the receive block based on the one ormore images. For instance, the adjustment at block 2004 may be similarto the adjustments described at block 912 of the method 900, along someor all the six DOF (e.g., up/down, left/right, forward/backward, roll,yaw, pitch) of the transmit block, the receive block, or both. Throughthis process, for instance, the present method may align the one or morelight sources with the one or more detectors.

In some scenarios, the process described for yaw or pitch alignment inthe description of images 1700 and 1800 is less suitable than othermethods herein. As an example, the variation in distances betweenadjacent light sources indicated by a first image (e.g., image 1000) andthe variation in distances between adjacent detectors indicated by asecond image (e.g., image 1100) may be insufficient for detection of yawor pitch offsets between the transmit block and the receive block. Forinstance, the one or more detectors (or the one or more light sources)may be arranged closely to one another. As another example, the transmitblock and the receive block may only include, respectively, one lightsource and one detector, similarly to the transmit block 620 and thereceive block 630 shown in FIG. 6C. Thus, in this example, there may beno adjacent light sources or adjacent detectors for the determination ofthe offsets described in the description of images 1700 and 1800.Accordingly, in some embodiments, alternative or additional processesfor rotational position alignment (e.g., yaw, pitch, roll) are presentedbelow.

In one embodiment, the receive block may be coupled to a half-mirrorpositioned along a receive path of the receive block. Referring back toFIG. 2B by way of example, the half-mirror may correspond to theentrance aperture 234 and may be configured to reflect at least aportion of light incident on the half-mirror, and the receive path maycorrespond to receive path 208. Further, in this embodiment, the cameramay be coupled to at least two light sources positioned along aperiphery of a camera lens of the camera. The at least two light sourcesmay be configured to emit light toward the LIDAR device. Further, inthis embodiment, the method 2000 may also involve causing the at leasttwo light sources to emit light pulses, and obtaining a third image fromthe camera indicative of reflections of the emitted light pulses off thehalf-mirror. In one instance, the method 2000 may also involvedetermining offsets between the reflections indicated by the thirdimage, and determining the rotational position adjustment accordingly.In another instance, the method 2000 may alternatively involve comparingthe third image with a stored image, and adjusting the relative positionbased on the comparison. For example, the stored image may indicateparticular pre-determined offsets between the reflected light pulsesthat correspond to a particular yaw, pitch, or roll of the receiveblock. In this example, the method 2000 may adjust the relative positionto achieve the particular offsets.

In another embodiment, the method 2000 may additionally or alternativelyinvolve actuating at least two probes adjacent to the receive blocktoward the receive block. A given probe (e.g., force sensor, proximitysensor, etc.) may be configured to provide a signal indicative ofcontact (or proximity) between the given probe and the receive block. Inthis embodiment, adjusting the relative position may comprise rotatingthe receive block (e.g., adjusting yaw, pitch, or roll of the receiveblock) such that at least two signals from the at least two probes areprovided at a substantially same time. For instance, the at least twoprobes may have a particular yaw or pitch substantially similar to theyaw or pitch of the transmit block, and thus by providing the at leasttwo signals at the substantially same time, the yaw or pitch of thereceive block may also correspond to the yaw or pitch of the transmitblock.

FIG. 21 illustrates a partial cross-section view of yet another system2100, according to an example embodiment. The system 2100 may be similarto any of the systems 100, 700, or 800. For instance, as shown, thesystem 2100 includes a LIDAR device 2104 that is similar to the LIDARdevices 104 and 704 the systems 100 and 700. It is noted that somecomponents of the system 2100 (e.g., alignment apparatus, mountingplatform, etc.) are omitted from the illustration of FIG. 21 forconvenience in description.

As shown, the LIDAR device 2104 has a configuration similar to the LIDARdevice 200. For instance, as shown, the LIDAR device 2104 includes atransmit block 2120, light sources 2122 a-c, receive block 2130,detectors 2132 a-c, an exit aperture 2134, and a lens 2150 that aresimilar, respectively, to the transmit block 220, the light sources 222a-c, the receive block 230, the detectors 232 a-c, the exit aperture234, and the lens 250 of the LIDAR device 200. However, in someexamples, the system 2100 may be adapted for use with other LIDAR deviceconfigurations such as the configuration of the LIDAR device 600, etc.Further, as shown, the system 2100 includes an actuator 2190 and probes2192-2194.

The actuator 2190 may be configured to move the probes 2192 and 2194toward the receive block 2130 in line with the discussion above at block2004 of the method 2000. Example actuators may include motors, pneumaticactuators, hydraulic pistons, relays, solenoids, and piezoelectricactuators among other possibilities.

The probes 2192 and 2194 may include any probes suitable for detectionof the receive block 2130 in line with the discussion above at block2004 of the method 2000. In one example, the probes 2192-2194 mayinclude force sensors that provide a signal if the probes 2192-2194contact the receive block 2130. In another example, the probes 2192-2194may include proximity sensors (e.g., IR range sensors, etc.) thatprovide a signal if the probes 2192-2194 are within a threshold distanceto the receive block 2130.

In the illustration of FIG. 21, a yaw of a component corresponds to anamount of rotation of the component about an axis of the componentpointing out of the page. Further, a pitch of the component correspondsto an amount of rotation of the component about an axis of the componentpointing away from the component. For instance, a pitch of the transmitblock 2120 may be the amount of rotation of the transmit block 2120about an axis perpendicular to one of the light sources 2122 a-c, apitch of the receive block 2130 may be the amount of rotation of thereceive block 2130 about an axis perpendicular to the exit aperture2134, and a pitch of the probe 2192 may be the amount of rotation of theprobe 2192 about an axis perpendicular to the probe 2192 that ispointing toward the receive block 2130, etc.

In line with the discussion above, the system 2100 provides an exampleembodiment for the rotational position alignment described at block 2004of the method 2000. Consider an example scenario where the probes2192-2194 have a particular yaw (i.e., amount of rotation about axispointing out of page) as shown in FIG. 21. In some examples, theparticular yaw may be substantially similar to the yaw of the transmitblock 2120. In one example, the probes 2192-2194 may be mounted via amounting apparatus (not shown) to the transmit block 2120. In thisexample, the mounting apparatus may have a particular structure thatcauses the probes 2192-2194 to have a substantially similar yaw to theyaw of the transmit block 2120. In another example, the probes 2192-2194may be mounted to an alignment apparatus (e.g., alignment apparatus 160,760, 860, etc.) that provides the particular yaw. For instance, thesystem 2100 may determine the yaw of the transmit block 2120 byprocessing an image from a camera (not shown) in line with thedescription of the image 1700 of FIG. 17. In turn, for instance, thesystem 2100 may adjust the particular yaw of the probes 2192-2194 byutilizing a robotic arm or other device coupled to the probes 2192-2194among other possibilities.

Continuing with the example scenario, the actuator 2190 may move theprobes 2192-2194 toward the receive block 2130 in line with thediscussion at block 2004 of the method 2000. On one hand, if the twoprobes 2192-2194 detect the receive block 2130 (e.g., provide a signal,etc.) at a substantially similar time, then the system 2100 maydetermine that the yaw of the receive block 2130 corresponds to the yawof the probes 2192-2192, and therefore also corresponds to the yaw ofthe transmit block 2120. On the other hand, if the two probes 2192-2194detect the receive block 2130 at substantially different times, then thesystem 2100 may determine that the yaw of the receive block 2130 doesnot correspond to the yaw of the probes 2192-2194, and therefore doesnot correspond to the yaw of the transmit block 2120. In this case, thesystem 2100 may then perform the adjustment of the relative positionbetween the transmit block 2120 and the receive block 2130 in line withthe discussion at block 912 of the method 900. Through this process, forexample, the transmit block 2120 and the receive block 2130 may bealigned with one another, at least with regard to the yaw DOF.

As a variation of the example scenario, the probes 2192-2194 may bearranged vertically (e.g., along an axis pointing out of the page)instead of the arrangement shown in FIG. 21, or the system 2100 mayinclude two additional probes (not shown) that are arranged vertically.In either case, the probes in this scenario may have a particular pitch(e.g., amount of rotation about an axis pointing away from the probes2192-2194 toward the receive block 2130). Similarly to the previousscenario, the particular pitch may also correspond to a pitch of thetransmit block 2120. Thus, in this scenario, a similar process to theprevious scenario may be performed by the system 2100 to align the pitchof the receive block 2130 with the pitch of the transmit block 2120.

As a further variation of the example scenarios above, the probes2192-2194 may be alternatively moved by the actuator 2192 toward thetransmit block 2120 instead of the receive block 2130. In this scenario,the system 2100 may adjust the position of the transmit block 2120 toalign the pitch and/or yaw of the transmit block 2120 with the pitchand/or yaw of the receive block 2130.

FIG. 22 illustrates a front-view of a camera 2206, according to anexample embodiment. The camera 2206 may be similar to the cameras 106,706, and 806 included, respectively, in the systems 100, 700, and 800.For instance, the camera 2206 may be located at a given position wherethe camera can capture images of light beams emitted by a LIDAR deviceand can capture images of detectors in the LIDAR device, similarly tothe cameras 106, 706, and 806. However, in some examples, the camera2206 may be located in other positions such as inside the housing of aLIDAR device, similarly to the probes 2192-2194 of the system 2100. Inthese examples, the camera 2206 may be configured to only capture imagesof the detectors in the LIDAR device, or may be configured to onlycapture images of light beams emitted by the LIDAR device, among otherpossibilities.

As shown, the camera 2206 includes a lens 2210 and light sources 2212,2214, 2216, and 2218. However, in some examples, the camera 2206 mayinclude additional, fewer, or different components than those shown. Inone example, the camera 2206 may alternatively not include the lens2210. For instance, the camera 2206 in this example may be an imagesensor configured to capture images without use of the lens 2210, amongother possibilities. In another example, the camera 2206 may bealternatively configured not to include the light sources 2212-2218, ormay be configured to include additional or fewer light sources than thefour light sources 2212-2218 shown, in accordance with the discussion atblock 2004 of the method 2000.

The lens 2210 may include one or more optical element (e.g., convexlens, concave lens, Fresnel lens, mirror, etc.) arranged to modify,condition, focus, and/or redirect light incident on the lens 2210 towardimaging sensors (not shown) of the camera 2206. In some examples, thelens 2210 may be configured to provide an infinity focus for incidentlight having a source wavelength. In one embodiment, the sourcewavelength is 905 nm. However, other source wavelengths are possible aswell (e.g., infrared, ultraviolet, x-ray, visible, etc.).

The light sources 2212-2218 may include laser diodes, light emittingdiodes (LEDs), vertical cavity surface emitting lasers (VCSEL), organiclight emitting diodes (OLEDs), polymer light emitting diodes (PLED),light emitting polymers (LEP), liquid crystal displays (LCD),microelectromechanical systems (MEMS), filament light sources, or anyother device configured to selectively transmit, reflect, and/or emitlight propagating away from the camera 2206. In some examples, the lightsources 2212-2218 may be configured to emit light at the sourcewavelength of light emitted by the LIDAR device (not shown) imaged bythe camera 2206. Referring back to FIG. 7A by way of example, the camera2206 may correspond to the camera 706 of the system 700. Thus, in thisexample, the light sources 2212-2218 may emit light having the sourcewavelength that can propagate through the light filter 708 similarly tolight emitted by the LIDAR device 704. However, in other examples, thelight sources 2212-2218 may be configured to emit light at otherwavelengths. For instance, the light filter may allow propagation of thelight from the light sources 2212-2218 even if the light has otherwavelengths, or the light filter may not be interposed between thecamera 2206 and the LIDAR device, similarly to the configuration shownin FIG. 7B, among other possibilities.

As shown, the light sources 2212-2218 are positioned along a peripheryof the camera lens 2210. However, in some examples, the light sources2212-2218 may be alternatively positioned at a different location. Inone example, referring back to FIG. 7A, the light sources 2212-2218 maybe alternatively positioned along a periphery of the light filter 708.In another example, referring back to FIG. 21, the light sources2212-2214 may be alternatively positioned within a housing of the LIDARdevice 2104 similarly to the probes 2192-2194. As a variation of theprevious example, the camera 2206 may be alternatively positioned insidethe housing of the LIDAR device 2104 as well similarly to the actuator2190. In yet another example, referring back to FIG. 21, the lightsources 2212-2218 may be alternatively positioned at a periphery of thetransmit block 2120 or at a periphery of the receive block 2130. Otherpositions for the light sources 2212-2218 are possible as well.

Thus, in some examples, the light sources 2212-2218 may be utilized by asystem of the present method to determine the at least one offset inline with the discussion at block 910 of the method 900, and thereforefacilitate the adjustment of the relative position between a transmitblock and a receive block of a LIDAR device in line with the discussionat block 912 of the method 900. In one example, the light sources2212-2218 may facilitate alignment of the rotational position (e.g.,yaw, pitch, roll) of a transmit block and a receive block in line withthe discussion at block 2004 of the method 2000.

As an example scenario for rotational position alignment using thecamera 2206, suppose that the camera 2206 corresponds to the camera 706of the system 700. In the scenario, the light sources 2212-2218 may beconfigured to emit light that propagates through the light filter 708(e.g., if the light filter 708 is interposed between the camera 2206 andthe LIDAR device 704 as illustrated in FIG. 7A). Suppose that, for thesake of example, the LIDAR device 704 has the configuration of the LIDARdevice 200 shown in FIG. 2B. In this example, the light from the lightsources 2212-2218 may propagate through the lens 250, and then reflectoff mirror 242 onto the entrance aperture 234. Further, suppose that, inthis example, the entrance aperture 234 includes a half-mirror thatreflects at least a portion of the light from the light sources2212-2218. In turn, the reflected light may reflect off the half-mirror,then reflect off the mirror 242, then propagate through the lens 250 ofthe LIDAR device, and then propagate into the lens 2210 of the camera2206. At this point in the scenario, the camera 2206 may capture animage of the reflected light in line with the discussion at block 2004of the method 2000.

Continuing with the scenario, a system of the present method may thenanalyze the image, in line with the discussion for images 1700-1800,using the properties (e.g., position, shape, intensity, etc.) of thelight beams originating from the light sources 2212-2218 to determineyaw or pitch offsets between the transmit block and the receive block.

As a variation of the scenario above, suppose that the light sources2212-2218 are alternatively positioned along a periphery of the transmitblock 220 of the LIDAR device 200. In this scenario, four mirrors may bepositioned at the positions shown for the light sources 2212-2218. Inturn, the four mirrors may reflect the light from the light sources2212-2218 towards the receive block 230 of the LIDAR device 200, and thecamera 2206 may capture an image of reflections of that light off theentrance aperture 234 (e.g., half-mirror) to determine a possibleyaw/pitch offset between the transmit block 220 and the receive block230.

As another variation of the scenario, suppose that the light sources2212-2218 are alternatively positioned along a periphery of the receiveblock 230 of the LIDAR device 200. In this scenario, a system of thepresent method may analyze an image of light from the light sources2212-2218 in line with the discussion for images 1600-1800 to determinethe rotational position (e.g., roll, yaw, pitch) of the receive block.

As yet another variation of the scenario, the light sources 2212-2218may be alternatively positioned along a periphery of the transmit block220 of the LIDAR device 200, and four additional similar light sourcesmay be positioned along the periphery of the receive block 230 of theLIDAR device 200. Similarly here, one or more images of the light fromthe light sources 2212-2218 and the four additional light sources may beobtained from the camera 2206 and analyzed by the system of the presentmethod to determine rotational offsets (e.g., roll, yaw, pitch) betweenthe transmit block and the receive block. Thus, various configurationsand positions are possible for the light sources 2212-2218 to facilitateoptics alignment in line with the discussion above.

It should be understood that arrangements described herein are forpurposes of example only. As such, those skilled in the art willappreciate that other arrangements and other elements (e.g. machines,interfaces, functions, orders, and groupings of functions, etc.) can beused instead, and some elements may be omitted altogether according tothe desired results. Further, many of the elements that are describedare functional entities that may be implemented as discrete ordistributed components or in conjunction with other components, in anysuitable combination and location, or other structural elementsdescribed as independent structures may be combined.

While various aspects and embodiments have been disclosed herein, otheraspects and embodiments will be apparent to those skilled in the art.The various aspects and embodiments disclosed herein are for purposes ofillustration and are not intended to be limiting, with the true scopebeing indicated by the following claims, along with the full scope ofequivalents to which such claims are entitled. It is also to beunderstood that the terminology used herein is for the purpose ofdescribing particular embodiments only, and is not intended to belimiting.

What is claimed is:
 1. A method comprising: mounting a transmit blockand a receive block in a light detection and ranging (LIDAR) device toprovide a relative position between the transmit block and the receiveblock, wherein the transmit block includes one or more light sourcesconfigured to emit light at a source wavelength, and wherein the receiveblock includes one or more detectors configured to detect light at thesource wavelength; locating a camera at a given position at which thecamera, when focused at infinity, can image light beams emitted by theone or more light sources and can image the one or more detectors;obtaining a first image using the camera located at the given positionand focused at infinity, wherein the first image is indicative of lightsource positions of the one or more light sources; obtaining a secondimage using the camera located at the given position and focused atinfinity, wherein the second image is indicative of detector positionsof the one or more detectors in the receive block; determining at leastone offset based on the light source positions indicated by the firstimage and the detector positions indicated by the second image; andadjusting the relative position between the transmit block and thereceive block based at least in part on the at least one offset.
 2. Themethod of claim 1, wherein the LIDAR device further includes a lensconfigured to (i) collimate light emitted from the one or more lightsources and (ii) focus light onto the one or more detectors, and whereinthe given position is such that the camera can image light beams emittedby the one or more light sources via the lens and can image the one ormore detectors via the lens.
 3. The method of claim 1, wherein adjustingthe relative position between the transmit block and the receive blockcomprises: rotating the receive block about an axis.
 4. The method ofclaim 1, wherein obtaining the first image comprises: obtaining thefirst image while the one or more light sources are emitting light atthe source wavelength.
 5. The method of claim 4, wherein obtaining thefirst image further comprises: obtaining the first image while a lightfilter is interposed between the camera and the one or more lightsources, wherein the light filter is configured to attenuate lightwithin a wavelength range that includes the source wavelength.
 6. Themethod of claim 1, wherein obtaining the second image comprises:obtaining the second image while the one or more light sources are notemitting light at the source wavelength and the one or more detectorsare illuminated with light at the source wavelength from an auxiliarylight source.
 7. The method of claim 1, further comprising generating acomposite image based on overlaying the first image and the secondimage, wherein the at least one offset is determined based on separationbetween one or more pixels in the composite image associated with alight source and one or more pixels in the composite image associatedwith a corresponding detector.
 8. The method of claim 1, whereinadjusting the relative position between the transmit block and thereceive block reduces the at least one offset.
 9. The method of claim 1,wherein adjusting the relative position between the transmit block andthe receive block causes the at least one offset to correspond to aparticular offset.
 10. The method of claim 1, further comprising:detecting a defect in a light source based on the first image.
 11. Themethod of claim 1, further comprising: detecting an aberration in anoptical element optically coupled to a light source based on the firstimage.
 12. The method of claim 1, wherein the receive block is coupledto a half-mirror positioned along a receive path of the receive block,wherein the camera is coupled to at least two light sources positionedalong a periphery of a camera lens of the camera and configured to emitlight toward the LIDAR device, the method further comprising: causingthe at least two light sources to emit light pulses; obtaining a thirdimage from the camera indicative of reflections of the emitted lightpulses off the half-mirror coupled to the receive block; and comparingthe third image with a stored image, wherein adjusting the relativeposition between the transmit block and the receive block is furtherbased on the comparison.
 13. The method of claim 1, further comprisingactuating at least two probes positioned adjacent to the receive blocktoward the receive block, wherein a given probe is configured to providea signal indicative of contact between the given probe and the receiveblock, wherein adjusting the relative position between the transmitblock and the receive block comprises rotating the receive block suchthat at least two signals from the at least two probes are provided at asame time.
 14. A system comprising: a mounting platform to mount a lightdetection and ranging (LIDAR) device that provides a relative positionbetween a transmit block in the LIDAR device and a receive block in theLIDAR device, wherein the transmit block includes one or more lightsources configured to emit light at a source wavelength, wherein thereceive block includes one or more detectors configured to detect lightat the source wavelength; a camera located at a given position at whichthe camera, when focused at infinity, can image light beams emitted bythe one or more light sources and can image the one or more detectors;an alignment apparatus configured to adjust the relative positionbetween the transmit block and the receive block; and a controllerconfigured to: obtain a first image from the camera located at the givenposition and focused at infinity, wherein the first image is indicativeof light source positions of the one or more light sources; obtain asecond image from the camera located at the given position and focusedat infinity, wherein the second image is indicative of detectorpositions of the one or more detectors in the receive block; determineat least one offset based on the light source positions indicated by thefirst image and the detector positions indicated by the second image;and cause the alignment apparatus to adjust the relative positionbetween the transmit block and the receive block based at least in parton the at least one offset.
 15. The system of claim 14, wherein theLIDAR device further includes a lens configured to (i) collimate lightemitted from the one or more light sources and (ii) focus light onto theone or more detectors, and wherein the given position is such that thecamera can image light beams emitted by the one or more light sourcesvia the lens and can image the one or more detectors via the lens. 16.The system of claim 14, further comprising: a light filter configured toattenuate light within a wavelength range that includes the sourcewavelength; and an actuator coupled to the light filter, wherein thecontroller is further configured to: cause the actuator to move thelight filter to a first position where the light filter is interposedbetween the camera and the one or more light sources; obtain the firstimage while the light filter is at the first position; cause theactuator to move the light filter to a second position where the lightfilter is outside a field-of-view of the camera; and obtain the secondimage while the light filter is at the second position.
 17. The systemof claim 14, further comprising: at least two light sources positionedalong a periphery of a camera lens of the camera and configured to emitlight toward the LIDAR device, wherein the receive block is coupled to ahalf-mirror positioned along a receive path of the receive block, andwherein the controller is further configured to: cause the at least twolight sources to emit light pulses; obtain a third image from the cameraindicative of reflections of the emitted light pulses off thehalf-mirror coupled to the receive block; and adjust the relativeposition between the transmit block and the receive block based also onthe third image.
 18. The system of claim 14, further comprising: atleast two probes positioned adjacent to the receive block, wherein agiven probe is configured to provide a signal indicative of contactbetween the given probe and the receive block, and wherein thecontroller is further configured to: control an actuator to move the atleast two probes toward the receive block; and cause the alignmentapparatus to rotate the receive block such that at least two signalsfrom the at least two probes are provided at a same time.
 19. The systemof claim 14, wherein causing the alignment apparatus to adjust therelative position between the transmit block and the receive blockreduces the at least one offset.
 20. The system of claim 14, wherein thecontroller is further configured to: detect an aberration in an opticalelement optically coupled to a light source based on the first image.